Your Eye Health

From general eye care to diseases of the eye and contact lens care, we have information for you. Please see below.

General Eye Care


It is common knowledge that a diet rich in fresh fruit and vegetables promotes good health. It is not as commonly known that the variety of colours in fruit and vegetables reflects the different health benefits we receive from them.

We know that we need to eat a balanced sensible diet for general physical health and well-being, but there are specific foods that contain vitamins which promote eye health and may even help to prevent certain eye diseases.

Vitamin A

Does a carrot a day keep the optometrist away? The short and simple answer is yes, to an extent. The orange colour in carrots comes from beta carotene, and carrots also contain large amounts of vitamin A, both of which contribute to eye health and help prevent macular degeneration and cataracts.

The idea that carrots contribute to good vision goes back to World War II. At that time, most foods were in short supply, but carrots were not. The British Royal Air Force credited eating carrots with their pilots’ increased ability to see the enemy in the dark. A rumour was set in motion to motivate more people to eat carrots.

Today, that view still exists, and there is some truth, as well as some exaggeration, to it.

Vitamin C

Vitamin C is an essential nutrient for over-all wellness and for the health of the eyes. In addition to providing antioxidants which fight disease, it can help slow down the development of cataracts and reduce the risk of macular degeneration.

Vitamin C and bioflavanoids work hand in hand in the body, and are thought to be most effective when taken together rather than separately. Bioflavanoids help the body to defend against seasonal allergies, which usually affect the eyes. Because they are the natural pigments that give fruit and vegetables their colour, they are found in almost any foods containing vitamin C, including citrus fruits, tomatoes, berries, tropical fruits and green leafy vegetables.

Vitamin E

Vitamin E is found in certain nuts and seeds, such as almonds, peanuts, pine nuts and sunflower seeds, and in dried apricots. It is believed to be an excellent antioxidant and to help against macular degeneration and cataracts.


Rhodopsin is a purple pigment that helps us to see in situations where the light is low. This nutrient is abundant in carrots as well as in certain berries.


As well as being found in spinach and turnip greens, lutein is found in the retina of the eye, making it an important role-player in healthy vision. Lutein is an antioxidant, and may help prevent age-related vision problems such as cataracts and macular degeneration.

Eating the right foods, particularly fruit and vegetables, can provide an excellent defence against vision problems that often occur later in life.

When eye injuries occur, knowing how to deal with them can mean the difference between minor eye damage and permanent injury, or even blindness. Here are some first aid suggestions for eye injuries. But, please remember, these suggestions are only first aid. It is important for you to contact your eye-care practitioner as soon as possible for any eye injuries.

If you have a foreign object in your eye, don’t rub it. Lift your upper eyelid outward and gently pull it down over the lower lash. This causes tears to flow which may wash the object out of your eye. You may have to repeat this several times. If the object does not wash out, contact your optometrist. Do not try to remove a particle that is embedded. You can cause more damage. If you are wearing contact lenses, remove the lens and clean it thoroughly before putting it back in your eye. If discomfort persists, remove, clean again and reapply. If discomfort continues, remove the lens and call your optometrist.

For chemicals splashed in your eyes, immediately flush your eyes with cool water for at least 15 minutes. If possible, hold your head under a slowly running tap, or pour water slowly from a glass or clear container. Seek professional attention immediately. If you are wearing contact lenses, remove them immediately. Then flush your eyes and seek professional help as described.

A blow to your face resulting in a black eye can be treated with cold compresses for about 15 minutes every hour. Your eye should be checked by your eye-care practitioner for internal damage. If the blow breaks your contact lenses, try to remove pieces of the lens immediately. Rinsing with water will help. Then call your optometrist.

Do not try to treat a cut, laceration or penetrating eye injury. Do not flush the eye with water or put any medicine in the eye. If you are wearing a contact lens, don’t try to remove it. Gently cover the eye with a bandage or gauze pad and go directly to your doctor or a nearby hospital.

Remember, the best way to treat eye injuries is to prevent them from happening in the first place. Don’t forget to be aware of potential eye hazards and wear appropriate eye protection.

During the infant and toddler years, your child has been developing many vision skills and has been learning how to see. In the preschool years, this process continues, as your child develops visually guided eye-hand-body coordination, fine motor skills and the visual motor skills necessary to learn to read.

As a parent, you should watch for signs that may indicate a vision development problem, including a short attention span for the child’s age; difficulty with eye-hand-body coordination in ball play and bike riding; avoidance of colouring and puzzles and other detailed activities.

There are everyday things that you can do at home to help your preschooler’s vision develop as it should.

These activities include reading aloud to your child and letting him or her see what you are reading; providing a chalkboard, finger paints and different shaped blocks and showing your child how to use them in imaginative play; providing safe opportunities to use playground equipment like a jungle gym and balance beam; and allowing time for interacting with other children and for playing independently.

By age three, your child should have a thorough optometric eye examination to make sure your preschooler’s vision is developing properly and there is no evidence of eye disease. If needed, your doctor can prescribe treatment including glasses and/or vision therapy to correct a vision development problem.

Here are several tips to make your child’s optometric examination a positive experience: 

  1. Make an appointment early in the day. Allow about one hour.

  2. Talk about the examination in advance and encourage your child’s questions.

  3. Explain the examination in your child’s terms, comparing the E chart to a puzzle and the instruments to tiny flashlights and a kaleidoscope.

Unless your optometrist advises otherwise, your child’s next eye examination should be at age five. By comparing test results of the two examinations, your optometrist can tell how well your child’s vision is developing for the next major step…into the school years.


Periodic optometric examinations are an important part of routine preventive health care. Many eye and vision conditions present no obvious symptoms. Therefore, individuals are often unaware that a problem exists. Early diagnosis and treatment are important for maintaining good vision and when possible preventing permanent vision loss.

The need for and frequency of optometric examinations varies with age, race, medical history, family history, occupation and other factors. Individuals with ocular signs or symptoms require prompt examination. In addition, the presence of certain risk factors may necessitate more frequent evaluations based on professional judgment.

Infants and Children

Newborns are typically screened at birth for congenital eye disorders and disease. In addition, all infants should receive an evaluation for vision problems and eye disease by an optometrist by six months of age or sooner if abnormalities or risk factors are present. Early diagnosis and treatment are important to assure proper visual development, to prevent vision loss due to eye disease and to manage hereditary or congenital eye disorders such as lazy eye or crossed eyes.

In the absence of specific problems or symptoms, re-examinations at age three and prior to entry into school are recommended. These examinations provide the opportunity to evaluate the level of a child’s visual development and can provide early diagnosis and intervention to prevent visual impairment due to various conditions.

At Risk: Infants born prematurely, with low birth weight, or whose mother had rubella, venereal disease, AIDS related infection or a history of substance abuse or other medical problems during pregnancy are at a particularly high risk for the development of eye and vision problems. Also, the presence of high refractive error or a family history of eye disease, crossed eyes or congenital eye disorders places infants and children at risk. 

School-aged Children 

Vision may change frequently during the school years. The most common problems are due to the development and progression of nearsightedness. In addition, the existence of eye focusing and/or eye coordination problems may affect school performance. Periodic examinations are recommended.

At Risk: Children failing to progress educationally or exhibiting reading and/or learning disabilities should receive an optometric examination as part of a multidisciplinary evaluation. 


During the adult years, the increased visual demands of our technological society bring about the need for regular optometric care. While the incidence of ocular disease is low for young adults, vocational and recreational visual demands are significant. To maintain visual efficiency, productivity, and optimum eye health, periodic examinations are recommended.

Adults, beginning in their early to mid-forties, can experience changes in their ability to see clearly at close distances. This normal aging change in the eye’s focusing ability will continue during the forties and fifties. In addition, increases in the incidence of eye health problems occur during these years. Therefore, periodic eye examinations are recommended.

At Risk: Individuals diagnosed with diabetes or hypertension, or who have a family history of glaucoma,  those who work in highly visually demanding or eye hazardous occupations, those taking certain systemic medications with ocular side effects or those with other health concerns or conditions.

Older Adults

Individuals age 61 or older have an increasing risk for the development of cataracts, glaucoma and macular degeneration and other sight threatening or visually disabling eye conditions as well as systemic health conditions. Therefore, annual eye examinations are recommended.

At Risk: Individuals diagnosed with diabetes or hypertension, or who have a family history of glaucoma or cataracts, and those taking systemic medications with ocular side effects or those with other health concerns or conditions.

Age Asymptomatic / Risk Free At Risk
Infants and toddlers
(birth to 24 months)
By 6 months of age By 6 months of age
or as recommended
(2 to 5 years)
At 3 years of age At 3 years of age
or as recommended
School age
(6 to 18 years)
Before first grade and every two years thereafter Annually
or as recommended
(19 to 40 years)
Every two to three years Every one to two years
or as recommended
(41 to 60 years)
Every two years Every one to two years
or as recommended
Older adult
(61 years and older)
Annually Annually
or as recommended

* Guidelines in this table may be insufficient for contact lens wearers.

Thousands of eye injuries, which often result in permanent vision loss, occur each year from accidents with fireworks. Be safe this year and enjoy the public fireworks displays that many communities sponsor. They are presented by highly skilled professionals and they are bigger, brighter and more beautiful than home displays, as well as much less dangerous.

If fireworks are legal where you live and you decide to set them off on your own, be sure to follow these important safety tips:

  • Never allow young children to play with or ignite fireworks, even sparklers.

  • Read and follow all warnings and instructions carefully.

  • Be sure other people are out of range before lighting fireworks.

  • Only light fireworks on a smooth, flat surface away from the house, dry leaves and flammable materials.

  • Never try to relight fireworks that have not fully functioned.

  • Keep a bucket of water handy in case of a malfunction or a fire.

  • Always wear safety goggles when lighting fireworks to protect your eyes from flying sparks and particles of debris (inexpensive goggles are available at most hardware stores).

In case of an eye injury from a fireworks accident, you should:

  • Seek professional attention from your eye care practitioner immediately (even for seemingly mild injuries).

  • Do not rub the injured eye. This will often cause more damage.

  • Protect the eye from pressure. In an emergency, you may tape the bottom of a foam cup or milk carton over the injured area until you can get professional attention.

  • Do not apply any ointment or medication without your practitioner’s instructions.

Here are some tips to help you wear your contact lenses and your cosmetics safely and comfortably together:

  • Put on soft contact lenses before applying makeup.

  • Put on rigid gas-permeable (RGP) lenses after makeup is applied.

  • Avoid lash-extending mascara, which has fibres that can irritate the eyes, and waterproof mascara, which cannot be easily removed with water and may stain soft contact lenses.

  • Remove lenses before removing makeup.

  • Choose an oil-free moisturizer.

  • Don’t use hand creams or lotions before handling your lenses. They can leave a film on your lenses.

  • Use hairspray before putting on your contact lenses. If you use hairspray while you are wearing your lenses, close your eyes during spraying and for a few seconds afterwards.

  • Blink your eyes frequently while under a hair drier or blower to keep your eyes from getting too dry.

  • Keep false eyelash cement, nail polish and remover, perfume and cologne away from the lenses. They can damage the plastic.

  • Choose water-based, hypo-allergenic liquid foundations. Cream makeup may leave a film on your lenses.

Parents and school teachers should be aware of the possibility of eye damage to children from hand-held laser pointers.

The light energy that laser pointers can aim into the eye can be more damaging than staring directly into the sun.

They are not toys, but are useful tools for adults that should be used by children only with adequate supervision.

Momentary exposure from a laser pointer, such as might occur from an inadvertent sweep of the light across a person’s eyes, causes only temporary flash blindness. However, even this can be dangerous if the exposed person is engaged in a vision-critical activity such as driving.

As one of today’s “older adults” you probably enjoy a more active lifestyle than people of your age ever have before and your eyes and vision play a major role in your lifestyle. You use your eyes while driving; enjoying recreational activities; reading; watching television; and performing many tasks that keep you living independently and productively.

But, as you mature, you may begin noticing subtle changes in your vision. Although they may cause some concern, some vision changes are normal and only a few conditions are sight threatening.

Here are some suggestions to help you understand your age-related vision limitations and compensate for them:

  • You will probably need more light for reading and other close tasks. Move a lamp closer to you or use a stronger wattage bulb.

  • When taking medication, be sure to read the label carefully and follow directions. Take your medication in a well-lit room to avoid confusing or mixing up medications.

  • Side vision and reaction time may reduce with age, so keep this in mind while you are driving or walking near traffic.

  • Limit night driving to well lighted roads; keep headlights and windshields clean; and be sure to keep your spectacles clean.

Age-related vision changes can’t be prevented, but they need not mean you must give up activities like driving or reading. By practicing good general health habits and having regular optometric eye examinations, you should be able to continue enjoying an active, productive and independent life.

Your baby has a whole lifetime to see and learn. But, did you know that your baby also has to learn to see? As a parent, there are many things that you can do to help your baby’s vision develop.  First, proper prenatal care and nutrition can help your baby’s eyes develop even before birth. At birth, your baby’s eyes should be examined for signs of congenital eye problems. These are rare, but early diagnosis and treatment are important to your child’s development.

At about age six months, you should take your baby to your optometrist for his or her first thorough eye examination. Things that the optometrist will test for include excessive or unequal amounts of nearsightedness, farsightedness, or astigmatism and eye movement ability as well as eye health problems. These problems are not common, but it is important to identify children who have them at this stage. Vision development and eye health problems can be more easily corrected if treatment is begun early.

Unless you notice a need, or your optometrist advises you otherwise, your child’s next examination should be around age three, and then again before he or she enters school.

Between birth and age three, when many of your baby’s vision skills will develop, there are ways that you can help.

During the first four months of life, your baby should begin to follow moving objects with the eyes and reach for things, first by chance and later more accurately, as hand-eye coordination and depth perception begin to develop.

To help, use a nightlight or other dim lamp in your baby’s room; change the crib’s position frequently and your child’s position in it; keep reach-and-touch toys within your baby’s focus, about eight to twelve inches; talk to your baby as you walk around the room; alternate right and left sides with each feeding; and hang a mobile above and outside the crib.

Between four and eight months, your baby should begin to turn from side to side and use his or her arms and legs. Eye movement and eye/body coordination skills should develop further and both eyes should focus equally.

You should enable your baby to explore different shapes and textures with his or her fingers; give your baby the freedom to crawl and explore; hang objects across the crib; and play “patty cake”and “peek-a-boo” with your baby.

From eight to twelve months, your baby should be mobile now, crawling and pulling himself or herself up. He or she will begin to use both eyes together and judge distances and grasp and throw objects with greater precision. To support development don’t encourage early walking – crawling is important in developing eye-hand-foot-body coordination; give your baby stacking and take-apart toys; and provide objects your baby can touch, hold and see at the same time.

From one to two years, your child’s eye-hand coordination and depth perception will continue to develop and he or she will begin to understand abstract terms. Things you can do are: encourage walking; provide building blocks, simple puzzles and balls; and provide opportunities to climb and explore indoors and out.

There are many other affectionate and loving ways in which you can aid your baby’s vision development. Use your creativity and imagination. Ask your optometrist to suggest other specific activities.


What is Low Vision? Few people are totally without sight. Most classified as blind today actually have some sight remaining and, thanks to developments in the field of low vision, can be helped to make good use of it.

Anyone with reduced vision is visually impaired, and can have problems functioning, ranging from minor to severe difficulty. There are two general classifications of low vision in use today:

  • partially sighted – visual acuity, that with best correction is still between 20/70 and 20/200 (a person with 20/70 eyesight must be 20 feet away to see clearly an object that a person with 20/20 eyesight can see clearly from 70 feet away);

  • legal blindness – visual acuity that cannot be corrected to better than 20/200 with conventional lenses and/or the patient has a restricted field of vision less than 20 degrees wide. 

Low vision impairments take many forms and exist in varying degrees. It is important to understand that the visual acuity alone is not a good predictor of the degree of the problem.

What Causes Low Vision?

Several eye diseases may be responsible for low vision, including:

    • Macular Degeneration – A disorder that affects the retina, the light sensitive lining at the back of the eye where images are focused. The macula -the area on the retina responsible for sharp central vision- deteriorates, gradually causing blurred vision, difficulty reading, and finally, a blind spot in the central area of vision. This is known as the “dry” form of macular degeneration, is age-related, and the leading cause of blindness in people over 50. The exact cause is unknown, but may be related to smoking, and possibly long-term exposure to high levels of the sun’s ultraviolet radiation and blue light. More rapid and severe vision loss comes from the “wet” form, when abnormal blood vessels develop under the macula and leak fluid and blood. There are also juvenile forms which are hereditary.
    • Diabetic Retinopathy – Diabetes can cause blood vessels that nourish the retina to leak, develop brush-like branches or enlarge. This can interfere with vision and, over time, may destroy the retina. Laser procedures and surgical treatments are used to reduce its progression.
    • Retinitis Pigmentosa – Gradually destroys night vision, severely reduces side vision, and may result in total blindness. An inherited disease, it usually produces its first symptom – night blindness – in childhood or adolescence.
    • Retrolental Fibroplasia (retinopathy of prematurity) – Occurs in infants born prematurely and, in some cases, is caused by high oxygen levels in incubators during the first 10 days of life.
    • Retinal Detachment – Can result in total blindness in the detached area of the affected eye. It involves the retina separating from its underlying layer. Causes are holes in the retina, eye trauma, infection, blood vessel disturbance or a tumour. Through early diagnosis, most detached retinas can be surgically re-attached with partial restoration of vision.
    • Cataracts – A clouding of part or all of the lens inside the eye. This prevents light from reaching the retina at the back of the eye, resulting in a generalized loss of vision. Causes are aging, long-term exposure to the sun’s ultraviolet radiation, injury, disease and inherited disorders. If the eye is healthy, the cataract can be surgically removed and vision restored, usually with intraocular lens implants. Cataract surgery has a high success rate but a small number of those for whom it is not successful will require low vision care.
  • Glaucoma – The internal pressure in the eye builds up because of problems with the flow or drainage of fluid within the eye, damaging the optic nerve and causing partial or total loss of sight. There are no early symptoms in the most common form, but the first signs of damage are side vision defects. Early diagnosis and treatment with drugs or sometimes surgery can minimize vision loss.

Vision can also be lost or damaged as a result of head injuries, brain damage and strokes.

What are the Most Common Types of Low Vision?

    • Loss of Central Vision – the centre of the person’s view is blurred or blocked, but side (peripheral) vision remains intact. This makes it difficult to read or recognize faces and most details in the distance. Mobility, however, is usually unaffected because side vision remains intact.
    • Loss of Side Vision – typified by an inability to distinguish anything to one side or both sides, or anything directly above and/or below eye level. Central vision remains, however, making it possible to see what is directly ahead. Typically, loss of side vision affects mobility and slows reading speed because the person sees only a few words at a time. Sometimes referred to as “tunnel vision.”
    • Blurred Vision – objects both near and far appear out of focus, even with the best conventional spectacle correction possible and even when the target is very large.
    • Generalized Haze – the sensation of a film or glare that may extend over the entire viewing field and may produce various patterns or areas of relatively severe vision loss.
    • Extreme Light Sensitivity – exists when standard levels of illumination overwhelm the visual system, producing a washed out image and glare disability. People with extreme light sensitivity may actually suffer pain or discomfort from relatively normal levels of illumination.
  • Night Blindness – inability to see outside at night under starlight or moonlight, or in dimly lighted interior areas such as movie theaters or restaurants.

Human eyes have a certain degree of natural protection, but every year, thousands of people suffer accidental eye injuries. Many injuries could be prevented if people would wear proper eye protection. Here are some types of safety eyewear that can protect your eyes from hazardous situations. Remember to wear the proper protection at work and when working around the house or yard.

Impact resistant spectacles provide limited protection from the front. Prescription eyewear should be impact-resistant, but this does not mean they are shatterproof.

Industrial strength safety glasses provide much more frontal protection against flying objects. They contain specially treated glass, plastic or polycarbonate lenses that meet industrial safety lens standards. Of all the materials, polycarbonate is the most impact resistant. These lenses should be mounted in special safety frames designed to hold the lenses securely in place under heavy impact. Studies show that lenses of more than 2mm thick are less likely to fall out of the frames under heavy impact. For additional protection, various types of side shields can be attached to the sides of the frames. Use with side shields for machining, light grinding or woodworking.

Safety goggles offer significant frontal and side protection against the danger of flying objects. If you wear glasses, you can wear most goggles over your regular glasses for protection and good vision. Use for heavy grinding and chipping.

Face shields protect your eyes from chemical splashes and from some flying particles, but they are not made for heavy impact. If you are working with highly toxic or unstable chemicals, you should wear goggles under the face shield. Use for laboratory work and liquid chemical handling.

Welding goggles and shields contain special absorptive or filter lenses for protection against welding rays, sparks or flying particles. Wear when welding or working around welding.

Sunglasses can protect your eyes against the harmful rays of the sun. To provide adequate protection sunglasses should:

  1. Block out 99 to 100 percent of both UV-A and UV-B radiation;

  2. Screen out 75 to 90 percent of visible light;

  3. Be perfectly matched in colour and free of distortion and imperfection;

  4. Have lenses that are gray, green or brown. 

If you wear contact lenses, you can now enjoy an added measure of protection. Contact lenses are now available with a UV blocking feature. These contact lenses should not be worn in place of your sunglasses, but do provide additional protection by blocking much of the UV radiation that can seep in from above and below your sunglasses. It is also a good idea to wear a hat or cap with a wide brim if you are in the sun. Sunglasses that are worn while you participate in eye hazardous work or sports should be made of 2mm thick polycarbonate.

Eye protection is also a major concern to all sports participants, especially those playing certain high risk sports. These include tennis, squash, ice hockey, badminton, archery, baseball/softball, fencing, boxing, karate and any sport with a projectile. There are many types of sports eyewear available in either prescription or non-prescription lenses. Ask your optometrist which one is best suited for your sport.

The lenses in your protective eyewear should provide clear, comfortable vision with little distortion. Excessively scratched, pitted or chipped lenses can lose their impact resistance and should be replaced. Eye protective equipment should fit snugly and correctly. Straps, frames and other parts should be durable and fit comfortably. Your optometrist can offer advice about what eye protection you need.

A good education for your child means good schools, good teachers and good vision. Your child’s eyes are constantly in use in the classroom and at play. So when his or her vision is not functioning properly, learning and participation in recreational activities will suffer.

The basic vision skills needed for school use are:

  • Near vision. The ability to see clearly and comfortably at 25-30 centimetres.

  • Distance vision. The ability to see clearly and comfortably beyond arm’s reach.

  • Binocular coordination. The ability to use both eyes together.

  • Eye movement skills. The ability to aim the eyes accurately, move them smoothly across a page and shift them quickly and accurately from one object to another.

  • Focusing skills. The ability to keep both eyes accurately focused at the proper distance to see clearly and to change focus quickly.

  • Peripheral awareness. The ability to be aware of things located to the side while looking straight ahead.

  • Eye/hand coordination. The ability to use the eyes and hands together.

If any of these or other vision skills is lacking or not functioning properly, your child will have to work harder. This can lead to headaches, fatigue and other eyestrain problems. As a parent, be alert for symptoms that may indicate your child has a vision or visual processing problem.

Be sure to tell your optometrist if your child frequently:

  • Loses their place while reading;

  • Avoids close work;

  • Holds reading material closer than normal;

  • Tends to rub their eyes;

  • Has headaches;

  • Turns or tilts head to use one eye only;

  • Makes frequent reversals when reading or writing;

  • Uses finger to maintain place when reading;

  • Omits or confuses small words when reading;

  • Consistently performs below potential.

Since vision changes can occur without you or your child noticing them, your child should visit the optometrist at least every two years, or more frequently, if specific problems or risk factors exist. If needed, the optometrist can prescribe treatment including spectacles, contact lenses or vision therapy.

Remember, a school vision or paediatrician’s screening is not a substitute for a thorough eye examination.


From the moment of birth, your child is learning to see. He or she progresses from the newborn’s blurry world of light and dark to the school-age child’s sophisticated ability to handle complex vision tasks. Toys, games and playtime activities help by stimulating this process of vision development.

Here is a list of toys and activities that can help your child develop or improve various vision skills.

Birth through 5 months:

  • Toys: Sturdy cot mobiles and gyms; bright large rattles and rubber squeaky toys.

  • Activities: Peek-a-boo; patty cake.

6 months through 8 months:

  • Toys: Stuffed animals; floating bath toys.

  • Activities: Hide and seek with toys.

9 months through 12 months:

  • Toys: Sturdy cardboard books; take-apart toys; snap-lock beads; blocks; stacking/nesting toys.

  • Activities: Roll a ball back and forth.

One-year olds:

  • Toys: Bright balls; blocks; zippers; rocking horse; riding toys pushed with the feet.

  • Activities: Throwing a ball.

Two-year olds:

  • Toys: Pencils, markers, crayons; bean bag/ring toss games; peg hammering toys, sorting games; puzzles; blocks.

  • Activities: Read to child; outdoor play; catch.

3 to 6 years:

  • Toys: Building toys with large snap-together pieces; stringing beads; puzzles; pegboard crayons; finger paints; chalk; large balls; modeling clay; simple sewing cards; tricycle; follow-the-dot games; sticker books and games.

  • Activities: Climbing, running; using a balance beam.

7 years and older:

  • Toys: Bicycle; skipping ropes, pogo sticks; roller skates; different size and shape balls; target games; remote controlled toys; complex puzzles;

  • Activities: Active sports; cycling.

When buying toys, remember to select those that are well-made and age appropriate. Provide proper eye safety equipment for older children and be certain that they wear protective eyeware when participating in eye hazardous sports and when using chemistry sets, tools or other items. Inexpensive homemade toys can be just as effective in helping children develop and improve their vision skills as expensive store bought ones.


Certain toys pose a serious threat to children’s vision; most injuries are preventable.

The following are guidelines for choosing safe toys for a child:

  • Avoid poorly designed toys with sharp, pointed or rough edges that can cut or poke.

  • Avoid poorly constructed toys with exposed nails or made of a brittle material that can shatter, sending splinters or sharp pieces into a child’s eyes.

  • Choose toy brooms, mops, sweepers and push toys with sticks that have rounded edges.

  • Select toys appropriate to the child’s age. Children under two should not have toys with stick handles. Those under six should not play with darts, arrows, catapults, other missile-throwing games or toys that eject missiles. Even those with suction cup tips can be unsafe in their hands.

  • Teach older children the proper way to play with darts, arrows, catapults and other missile-throwing toys and supervise their play.

  • Require older children and teens to wear safety goggles when playing or working with chemistry sets, some hobby kits, workshop tools, rifles and pellet guns. These safety goggles can be purchased at hardware, hobby and department stores.

  • Be certain children have and wear the proper goggles when using minibikes, skate boards and roller skates.

Your optometrist may prescribe eyedrops and/or ointments for you to use to treat certain eye conditions, infections or diseases. Before you use these, be sure to tell your optometrist about any other prescription or non-prescription medications that you are taking or any allergies that you have.

Here are some general tips about correctly putting eyedrops in your eyes:

  1. Always wash your hands before handling medications

  2. Look at the ceiling by standing or sitting and tilting your head backwards. Some people like to lie down on a flat surface.

  3. The best way to ensure the drop remains in your eye is to gently pull the skin of your lower eyelid between your thumb and index finger to create a “pocket” for the drop. If you are unable to master this, gently pull your lower lid down with your index finger.

  4. Look up (so you are not looking directly at the bottle) and gently release a drop into the pocket of your eye. Keep the bottle’s nozzle or the eyedropper clean by not touching it to any part of your eyes.

  5. If you are unable to get the drop into your eye because of blinking, try this: Close your eye and pull the lower lid down. Aim the drop into the inside corner of your eye. Open your eye and let the drop run into your lower lid. (Be sure to try the open-eye method at your next scheduled dose as it is a more reliable way to ensure the drop remains in your eye).

  6. To help keep the medication in your eye and prevent it from escaping through the tear duct, your optometrist may instruct you to “occlude” this duct by gently pressing on the inside corner of your closed eye with your index finger for about three minutes. If drops have been placed in both eyes, you can perform occlusion by placing your thumb and index finger (or the index fingers of both hands) on either side of your nose and gently pressing down on the inside corners of both closed eyes. This step is very important with some medications, so do not skip it if your optometrist specifies it.

  7. Gently blot your closed eyes with a tissue to wipe away any excess drops.

  8. If you use more than one kind of drop, wait at least five minutes between drops.

Here are some general tips about correctly putting ointment in your eyes.

  1. Begin by expressing and discarding a ½cm of ointment from the tube at each use.

  2. If applying to your eye’s surface, form a pocket by gently pulling the skin of your lower eye-lid between your thumb and index finger to create a pocket for the ointment. Then express a ½cm to 1cm strip of ointment into the pocket (unless your optometrist prescribes a different amount).

  3. Twist your wrist to break the strip of ointment from the tube.

  4. After placing the ointment in your eye, blink or close your eyes briefly. Your body heat will melt the ointment so it can spread across the surface of your eyes.

  5. If you are applying the ointment to the edges of your eyelids, express about a 1cm strip of ointment onto your finger and glide it across the length of your closed lids near the base of your lashes.

  6. Use a soft, clean tissue to remove any excess ointment from the skin around your eyes. Be sure not to disturb the ointment placed in your eyes or on the edges of your eyes.

Be sure to follow all the instructions that your optometrist gives you and to complete the course of medication he or she prescribes. If you experience any side-effects, (such as burning, inflammation, puffiness, itching, etc.) call your optometrist immediately.

Do you wish you could improve your batting average in the weekend cricket league; cut a few strokes off your golf score; or take your tennis game to the next level? Vision, just like speed and strength, is an important ingredient in how well you play your sport.

Your vision is composed of many skills, and just as excercise and practice can increase your speed and strength, it can improve your vision skills. You can select from the list below to see explanations of specific vision skills and tips to improve them.

The definitions and suggestions that follow are general and should not be considered complete or thorough. They are to give you a general idea of the types of excercises that can be helpful when incorporated into a total program of sports vision care.

Some athletes will have visual difficulties that will need individual, professional attention and will not benefit from these exercises alone. An evaluation by a sports vision optometrist can pinpoint your individual problems and needs as related to your sport.

Remember, a thorough eye examination by your optometrist is a great place to begin “getting the winning edge.”

  • In racquet sports, Depth Perception  enables you to quickly and accurately judge the distance between yourself, the ball, your opponents, teammates, boundary lines and other objects. When you are shooting or hunting, if you consistently over or underestimate the distance to your target, poor depth perception may be at fault.

    You can work to improve depth perception by having a friend hold a straw about a ½ metre in front of you, parallel to the ground. Practice inserting a toothpick into the hole.

  • If you are playing a sport like tennis, soccer, rugby or hockey, it is important that you be able to clearly see objects while you and/or the objects are moving fast. Without good Dynamic Visual Acuity, you are going to have a difficult time in sports like these.

    To improve dynamic visual acuity, cut different size letters out of a magazine and stick them on a stereo turntable and try to identify them (from about arm’s length) at 33, 45 and 78 rpms. As it gets easier, use smaller letters.

  • When you are playing any sport with a ball or a fast moving opponent, it is important that you be able to follow objects without much head motion. Eye Tracking helps you maintain better balance and react to the situation more quickly.

    One way to improve eye tracking is to keep a book balanced on your head while following the flight of a ball or object that is thrown or hit.

    With the book on your head, you can also follow a tennis ball as it rolls slowly around the inside of a Frisbee. After you master the softball, replace it with a faster moving golf ball.

  • Eye-Hand-Body Coordination is how your hands, feet and body and other muscles respond to the information gathered through your eyes. It is an important part of most sports because it affects both timing and body control.

    To improve your eye-hand-body coordination, try jumping up and down on an old mattress while someone tosses a tennis ball to you from a variety of unpredictable angles. Catch it and toss it back.

    You can also paste a small target on a stereo turntable and try to accurately touch the target with a pointer at speeds of 33, 45 and 78 rpm. As you improve, you can make the target smaller.

  • The split second that it takes you to change focus from an object far away to one near you may delay your reaction time and cause you to frequently drop a pass or mis-hit an easy volley.

    To improve Focus Flexibility, stick a newspaper page on a wall at eye level about 5 metres away from you and hold a similar one in your hand about 40 cm from your face, at the same height but slightly to one side, so you can see both pages.

    Focus on a headline on the page on the wall and then try to quickly change to focus on the page near your face. Keep changing focus back and forth and you will improve your ability to change focus quickly. If you find it getting easier, move the paper in your hand closer to your face.

  • When a soccer player sees a teammate out of the corner of his eye, he is using his Peripheral Vision. Since much of what happens in sports does not happen directly in front of you, it’s important to increase your ability to see action to the side without having to turn your head.

    To increase your ability to see things while you are not looking directly at them, try watching TV with your head turned to one side and then the other. If you are watching a game live, you can turn your head to one side and see if you can still follow the action.

  • When you commit an error on an easy ground ball or miss a short putt, it may be that you are distracted by things that are happening around you. Our eyes normally react to anything that happens in our field of vision….spectators, other participants and even the wind blowing leaves on an overhanging branch. Visual Concentration is the ability to screen out these distractions and stay focused on the ball or the target.

    To improve your concentration, practice your sport while a friend is standing nearby waving his or her arms and moving at erratic intervals. You can also practice in a darkened room with a strobe light pulsating slowly. These exercises can help your eyes to remain fixed on their target in spite of other movement around you.

  • When you are pushing a fast break up the basketball court, leading a rush up the ice in hockey, or catching the big wave amid a crowd of surfers, you need to process and remember a fast moving, complex picture of people and things. This is called Visual Memory. The athlete with good visual memory always seems to be in the right place at the right time.

    To improve your visual memory, try paging through a magazine, glancing briefly at each visually complicated ad or illustration, then turning the page and reconstructing the images from memory. When this becomes easy, wait 5 seconds (then 10, etc.) before starting to reconstruct the image.

  • The bowler releases the ball and you swing…a little late and you are caught behind…or worse you miss the ball completely. Or, maybe you just can’t quite return that tennis serve. You need to improve your Visual Reaction Time, or the speed with which your brain interprets and reacts to your opponent’s action.

    Stand with your back to a friend. Have that person carefully throw a tennis ball or football and yell “now.” When you hear the yell, turn around, find the ball and try to catch it. If you do this repeatedly, you can train your brain to interpret and react faster.

  • Picture yourself hitting a perfect drive…long and right down the middle of the fairway. Believe it or not, picturing yourself doing it can actually help you do it. Visualization is the skill that enables you to see yourself performing well in your “mind’s eye” while your eyes are seeing and concentrating on something else, usually the ball. Using scanning techniques, researchers have found that the same areas of the brain that light up during performance also do so when you visualize the performance.

Always wear the proper eye protection for your sport. When appropriate, use proper eye protection when you are trying these excercises. Your optometrist can advise you about what is best for you.

The sun supports all life on our planet; however, its life-giving rays also pose dangers.

The principal danger is in the form of ultraviolet (UV) radiation. UV radiation is a component of solar energy, but it can also be given off by artificial sources like welding machines, tanning beds and lasers.

UV radiation is divided into UV-A, UV-B and UV-C. UV-C is absorbed by the ozone layer and does not present any threat (man made sources of UV-C, like electric welding arcs, are very harmful to the eyes, if you do not use the proper protection). That’s not true of UV-A and UV-B. Scientific evidence now shows that exposure to both UV-A and UV-B can have damaging long and short term effects on your eyes and vision.

If you are exposed, unprotected, to excessive amounts of UV radiation over a short period of time, you are likely to experience a condition called photokeratitis. Like a “sunburn of the eye” it may be painful and you may have symptoms including red eyes, a foreign body sensation or gritty feeling in the eyes, extreme sensitivity to light and excessive tearing. Fortunately, this is usually temporary and rarely causes permanent damage to the eyes.

Long term exposure to UV radiation can be more serious. Scientific research has shown that exposure to even small amounts of UV radiation over a period of many years may increase your chance of developing a clouding of the lens of the eye called a cataract and can cause damage to the retina, the nerve-rich lining of your eye that is used for seeing. Damage to the lens or the retina is usually not reversible.

The effects of UV radiation are cumulative. The longer your eyes are exposed to UV radiation, the greater the risk of developing conditions such as cataracts in later life. Therefore, you should wear quality sunglasses that offer good protection and a hat or cap with a wide brim whenever you are working outdoors, participating in outdoor sports, taking a walk, running errands or doing anything in the sun.

To provide protection for your eyes, your sunglasses should:

  • block out 99 to 100 percent of both UV-A and UV-B radiation;

  • screen out 75 to 90 percent of visible light;

  • be perfectly matched in color and free of distortion and imperfection; and

  • have lenses that are gray, green or brown.

If you spend a lot of time outdoors in bright sunlight, wrap around frames provide additional protection from the harmful UV radiation.

People who wear or are interested in wearing contact lenses can now enjoy an added measure of protection. Contact lenses with a UV-blocking feature are now available. These contact lenses should not be worn in place of your sunglasses, but they do provide excellent added protection by blocking much of the UV radiation that can seep in from the top, bottom and sides of your sunglasses. With the small, round lenses found in many trendy frames, wearing UV-blocking contact lenses is an added measure of protection against potentially harmful UV radiation.

Contact lenses with UV-blocking also provide UV protection against indoor UV radiation emitted by sources such as high wattage halogen and fluorescent lighting. By wearing UV-blocking contact lenses, your eyes will also be protected indoors when you are less likely to be wearing sunglasses.

Don’t forget protection for children and teenagers. They typically spend more time in the sun than adults.


If one or more of the following factors fits you, you could be in a higher risk category for damage to your eyes from UV radiation:

  • Do your spend a great deal of time outdoors?

  • Do you spend time skiing, mountain climbing or at the beach?

  • Do you use a sunlamp or tanning parlor?

  • Do you live at high altitude?

  • Are you a welder, medical technologist or do you work in the graphic arts or in the manufacture of electronic circuit boards?

  • Do you take prescription or over the counter drugs that can increase your sensitivity to UV radiation (check with your optometrist, pharmacist or physician)?

  • Have you had cataract surgery in one or both eyes?

Be sure to see your optometrist regularly for a thorough eye examination. It is a good way to monitor your eye health, maintain good vision and keep up to date with new advances in UV protection.

Contact Lens Information

Contact lenses are medical devices that, when placed on the eye can correct shortsightedness, farsightedness and astigmatism. They can also be worn for cosmetic or therapeutic reasons.

People choose to wear contact lenses for many reasons. Aesthetics and cosmetics are often motivating factors for people who would like to avoid wearing glasses or would like to change the appearance of their eyes. Other people wear contacts for more visual reasons. When compared with spectacles, contact lenses typically provide better peripheral vision, and do not collect moisture such as rain, snow, condensation, or sweat. This makes them ideal for sports and other outdoor activities.

Additionally, there are conditions such as keratoconus and aniseikonia that are better corrected with contact lenses than glasses.

Although contact lenses have been available for over a century, the development of PMMA (polymethyl methacrylate) or Perspex promoted the development of plastic corneal hard contact lenses. In 1971 the first soft contact lens was approved by the American Food and Drug Administration. Since then the advancements in both material and design have made contact lenses first choice for over 15% of the world’s population.

The prescribing of contact lenses is restricted to eye-care practitioners (Optometrists and Ophthalmologists). The best type of lens will be prescribed based on your visual requirements, eye structure and tear quality. Although your contact lens prescription is usually similar to your spectacle prescription the two are not interchangeable.

The many types of contact lenses currently available can be grouped in various ways according to:

  • Function
  • Material
  • Wearing schedule
  • Design of the lens

Prescription contact lenses

Corrective contact lenses are designed to improve vision. Conditions correctable with contact lenses are myopia (shortsightedness), hypermetropia (farsightedness), astigmatism and presbyopia.

Cosmetic contact lenses

A cosmetic contact lens is designed to change the appearance of the eye. These lenses are available with or without prescription and carry the same risk of complications as any other contact lens. It is for this reason that even zero-powered lenses are classified as medical devices and a contact lens examination is essential before first use.

Therapeutic contact lenses

Contact lenses may be used in the management and treatment of various disorders of the eye. For example, a bandage contact lens is used to prevent the eyelid rubbing against an injured or diseased cornea.

Hard lenses are made from a rigid plastic material called PMMA. Their main disadvantage is that no oxygen is transmitted through the lens to the cornea.

RGP (Rigid Gas Permeable) lenses started development during the 1980s. Their rigid structure and high oxygen transmission make them ideal for higher prescriptions and patients with keratoconus. In addition, RGP lenses are not hydrophilic and do not absorb vapours or liquids, making them suitable for use in many industrial environments.

Soft lenses are made from gel-like, water-containing plastics. Whilst rigid lenses require a period of adaptation, soft lenses are immediately comfortable.

Daily Wear lenses are designed to be removed prior to sleeping.

Extended Wear lenses can be worn overnight, usually for 6 or more nights. These lenses can be worn for such long periods of time because of their high oxygen permeability to the cornea, which allows the eye to remain healthy even when the eyelid is closed. However, Extended lens wearers may have an increased risk for corneal infections and corneal ulcers, primarily due to poor care and cleaning of the lenses, tear film instability, and bacterial stagnation.

Daily disposable lenses – Discard after a single day of wear.

Shorter replacement cycle lenses are commonly thinner and lighter, due to lower requirements for durability against wear and tear, and may be the most comfortable in their respective class and generation. These may be best for patients with ocular allergies or other conditions because it limits deposits of antigens and protein, and is considered the healthiest wear schedule due to the most frequent replacement. Single use lenses are also useful for people who use contacts infrequently, or for purposes (e.g., swimming or other sporting activities) where losing a lens is likely.

Disposable lenses – Discard every two to four weeks as prescribed by your practitioner.

Frequent replacement lenses – Discard monthly or quarterly as prescribed by your practitioner.

Traditional (reusable) lenses – Discard every six months or longer as prescribed by your practitioner.

Many lens designs are available to correct various types of vision problems:

Spherical contact lenses are prescribed to correct myopia (shortsightedness) or hyperopia (farsightedness).

Toric contact lenses are used to correct astigmatism.

Multifocal contact lenses contain different zones for near and far vision to correct presbyopia.

Lenses are available in a multitude of combinations of diameter, curvature and material. Your Optometrist will judge the best lens for you based on good vision, fit, comfort and wearing schedule. He/she will also ensure that the final lenses prescribed will not interfere with the physiology of the eye.

Cleaning and disinfecting contact lenses is usually carried out by storing in multipurpose or preservative-free hydrogen peroxide solutions.

Daily disposable contact lenses do not need cleaning or disinfecting. They are stored in sterile containers and discarded after use.

People react differently to various lens materials and cleaning solutions. In most cases, if a problem develops, a change in lens type, material or cleaning solution is all that is needed to provide comfort, good vision and healthy eyes.

If you experience any discomfort, remove your lenses and consult your Optometrist.

Common Eye Conditions

Astigmatism means that a corneal or lens surface is oval like a rugby ball instead of spherical like a basketball. Most astigmatic surfaces have two curves – a steeper curve and a flatter curve. This causes light to focus on more than one point in the eye, resulting in blurred vision at distance or near. Astigmatism often occurs along with nearsightedness or farsightedness.

Signs and Symptoms

Blurred vision (near and distance)

Detection and Diagnosis

Astigmatism can be detected and measured with corneal topography, keratometry, vision testing and refraction.


Astigmatism can be corrected with glasses, contact lenses, or surgically. The most common surgeries used to correct corneal astigmatism are astigmatic keratotomy (procedures that involve placing a microscopic incision on the cornea) and LASIK. The objective of these procedures is to reshape the cornea so it becomes more spherical or uniformly curved.

A guide to the many parts of the human eye and how they function.

The ability to see is dependent on the actions of several structures in and around the eyeball. The graphic below lists many of the essential components of the eye’s optical system.

anatomy external

anatomy globe

When you look at an object, light rays are reflected from the object to the cornea, which is where the miracle begins. The light rays are bent, refracted and focused by the cornea, lens, and vitreous. The job of the lens is to make sure the rays come to a sharp focus on the retina. The resulting image on the retina is upside-down. Here at the retina, the light rays are converted to electrical impulses which are then transmitted through the optic nerve, to the brain, where the image is translated and perceived in an upright position!

eye emmetrop

Think of the eye as a camera. A camera needs a lens and a film to produce an image. In the same way, the eyeball needs a lens (cornea, crystalline lens, vitreous) to refract, or focus the light and a film (retina) on which to focus the rays. If any one or more of these components is not functioning correctly, the result is a poor picture. The retina represents the film in our camera. It captures the image and sends it to the brain to be developed. The macula is the highly sensitive area of the retina. The macula is responsible for our critical focusing vision. It is the part of the retina most used. We use our macula to read or to stare intently at an object.


Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Farsightedness or hyperopia, occurs when light entering the eye focuses behind the retina, instead of directly on it. This is caused by a cornea that is flatter, or an eye that is shorter, than a normal eye. Farsighted people usually have trouble seeing up close, but may also have difficulty seeing far away as well.

eye hyper

Young people with mild to moderate hyperopia are often able to see clearly because their natural lens can adjust, or accommodate to increase the eye’s focusing ability. However, as the eye gradually loses the ability to accommodate (beginning at about 40 years of age), blurred vision from hyperopia often becomes more apparent.

Signs and Symptoms

  • Difficulty seeing up close
  • Blurred distance vision (occurs with higher amounts of hyperopia)
  • Eye fatigue when reading
  • Eye strain (headaches, pulling sensation, burning)
  • Crossed eyes in children

Detection and Diagnosis

Hyperopia is detected with a vision test called a refraction. Very young patients may require cycloplegic eyedrops prior to this test so that they are unable to mask their farsightedness with accommodation.


The treatment for hyperopia depends on several factors such as the patient’s age, activities, and occupation. Young patients may or may not require glasses or contact lenses, depending on their ability to compensate for their farsightedness with accommodation. Glasses or contact lenses are required for older patients.

Refractive surgery is an option for adults who wish to see clearly without glasses. LASIK, clear lens replacement, LTK and intraocular contact lenses are all procedures that can be performed to correct hyperopia.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Nearsightedness or myopia, occurs when light entering the eye focuses in front of the retina instead of directly on it. This is caused by a cornea that is steeper, or an eye that is longer, than a normal eye. Nearsighted people typically see well up close, but have difficulty seeing far away.

eye myopicThis problem is often discovered in school-age children who report having trouble seeing the chalkboard. Nearsightedness usually becomes progressively worse through adolescence and stabilizes in early adulthood.

Signs and Symptoms

  • Blurry distance vision
  • Vision seems clearer when squinting

Detection and Diagnosis

Nearsightedness is detected with a vision test and refraction.


The treatment for nearsightedness depends on several factors such as the patient’s age, activities, and occupation. Vision can be corrected with glasses, contact lenses or surgery. Refractive procedures such as LASIK can be considered for adults when the prescription has remained stable for at least one year.

Presbyopia is a term used to describe an eye in which the natural lens can no longer accommodate. Accommodation is the eye’s way of changing its focusing distance: the lens thickens, increasing its ability to focus close-up. At about the age of 40, the lens becomes less flexible and accommodation is gradually lost. It’s a normal process that everyone eventually experiences.

Most people first notice difficulty reading very fine print such as the phone book, a medicine bottle, or the stock market page. Print seems to have less contrast and the eyes become easily fatigued when reading a book or computer screen. Early on, holding reading material further away helps for many patients. But eventually, reading correction in the form of reading glasses, bifocals, or contact lenses is needed for close work. However, nearsighted people can simply take their glasses off because they see best close-up.

Signs and Symptoms

  • Difficulty seeing clearly for close work
  • Print seems to have less contrast
  • Brighter, more direct light required for reading
  • Reading material must be held further away to see (for some)
  • Fatigue and eyestrain when reading

Detection and Diagnosis

Presbyopia is detected with vision testing and a refraction.


The treatment for presbyopia is very simple, but is entirely dependent on the individual’s age, lifestyle, occupation, and hobbies. If the patient has good distance vision and only has difficulty seeing up close, reading glasses are usually the easiest solution. For others, bifocals, trifocals and varifocals (glasses with reading and distance correction) or separate pairs of reading and distance glasses are necessary. Another option is monovision: adjusting one eye for distance vision, and the fellow eye for reading vision. This can be done with contact lenses or permanently with refractive surgery.

With acknowledgement to St. Lukes Eye Hospital.

Strabismus is a problem caused by one or more improperly functioning eye muscles, resulting in a misalignment of the eyes. Normally, each eye focuses on the same spot but sends a slightly different message to the brain. The brain superimposes the two images, giving vision depth and dimension. Here’s an easy way to see how the eyes work together: hold your finger at arm’s length. While looking at your finger, close one eye, then the other. Notice how your finger changes position. Even though the images are slightly different, the brain interprets them as one.

Each eye has six muscles that work in unison to control movements. The brain controls the eye muscles, which keep the eyes properly aligned. It is critical that the muscles function together for the brain to interpret the image from each eye as a single one.

Strabismus must be detected early in children because they are so adaptable. If a child sees double, his or her brain quickly learns to suppress or block out one of the images to maintain single vision. In a very short time, the brain permanently suppresses vision from the turned eye, causing a weak or amblyopic eye. Children may also develop a head tilt or turn to compensate for the problem and eliminate the double image. Unlike children, adults with a newly acquired strabismus problem typically see double.

There are many causes of strabismus. It can be inherited, or it may be caused by trauma, certain diseases, refractive errors and sometimes eye surgery.

Signs and Symptoms

Adults are much more likely to be bothered by symptoms from strabismus than young children. It is unusual for a child to complain of double vision. Children should undergo vision screening examinations to detect problems early. The younger the child is when strabismus is detected and treated, the better the chance of normal vision. The following are common signs and symptoms:

  • Turned or crossed eye
  • Head tilt or turn
  • Squinting
  • Double vision (in some cases)

Detection and Diagnosis

Strabismus is detected with a comprehensive eye examination and special tests used to evaluate the alignment of the eyes.


The appropriate treatment for strabismus is dependent on several factors including the patient’s age, the cause of the problem, and the type and degree of the eye turn. Treatment may include patching, corrective glasses and prisms, together with vision therapy or, as a last resort, surgery.

Vision therapy, together with possible refractive error correction, attempts to teach the brain to utilise both eyes together as a team. For this treatment to be effective, it must be done at a young age before the child can develop amblyopia.

Surgery is sometimes performed for both adults and children to straighten a crossed eye. The procedure may be done with local or general anaesthesia. There are several different surgical techniques used to correct strabismus. The appropriate one is dependent on the muscle involved and the degree of the eye turn.

With acknowledgement to St. Lukes Eye Hospital.

Diseases of the Eye

Basal cell carcinoma is a type of skin cancer that occurs most commonly on the face or neck, often near an eyelid or on the nose. The tumor cells are thought to originate from the basal, or innermost, layer of the skin.

Basal cell carcinoma is one of the most common type of skin cancer. Fair-skinned people over age 50 are most commonly affected; it is rare among those with dark skin. The incidence increases significantly with sun exposure. Those who work outdoors or live in sunny climates or areas with high sun exposure are at greater risk.

The ultraviolet radiation in sunlight is believed to be the cause in most cases. People with dark complexions have more melanin in their skin and are able to absorb higher amounts of the damaging ultraviolet rays. Since those with fair skin have less melanin, they are less able to withstand the effects of UV exposure.

Signs and Symptoms

  • Typically appears on the eyelid (the lower lid is more common than the upper)
  • Begins as a small, raised growth
  • Classic appearance is a nodule with a pitted center
  • Tumor edges may have a “pearly” appearance
  • Does not cause discomfort, but if advanced, may cause lid to turn in or out

Detection and Diagnosis

If left untreated, the growth may gradually invade the surrounding tissue. Fortunately, basal cell carcinomas rarely metastasize (spread to other parts of the body). Diagnosis is made by microscopic examination of the tumor cells.


Basal cell carcinoma can be removed surgically or with radiation. As with any type of cancer, early detection is important. Consult with an eye care practitioner or dermatologist about any suspicious growth appearing on the eyelids or skin.


Individuals at risk, especially the fair-skinned, should avoid overexposure to sunlight. Wear sunglasses to protect the delicate skin around the eyelids from UV light. Protective clothing, headgear, and sunscreen are also advisable when spending time outdoors.

A corneal ulcer forms when the surface of the cornea is damaged or compromised. Ulcers may be sterile (no infecting organisms) or infectious. The term infiltrate is also commonly used along with ulcer. Infiltrate refers to an immune response causing an accumulation of cells or fluid in an area of the body where they don’t normally belong.

Whether or not an ulcer is infectious is an important distinction for the physician to make and determines the course of treatment. Bacterial ulcers tend to be extremely painful and are typically associated with a break in the epithelium, the superficial layer of the cornea. In some cases, the inflammatory response involves the anterior chamber along with the cornea. Certain types of bacteria, such as Pseudomonas, are extremely aggressive and can cause severe damage and even blindness within 24-48 hours if left untreated.

Sterile infiltrates on the other hand, cause little if any pain. They are often found near the peripheral edge of the cornea and are not necessarily accompanied by a break in the epithelial layer of the cornea.

There are many causes of corneal ulcers. Contact lens wearers (especially soft) have an increased risk of ulcers if they do not adhere to strict regimens for the cleaning, handling, and disinfection of their lenses and cases. Soft contact lenses are designed to have very high water content and can easily absorb bacteria and infecting organisms if not cared for properly. Pseudomonas is a common cause of corneal ulcer seen in those who wear contact lenses.

Bacterial ulcers may be associated with diseases that compromise the corneal surface, creating a window of opportunity for organisms to infect the cornea. Patients with severely dry eyes, difficulty blinking, or who are unable to care for themselves, are also at risk. Other causes of ulcers include: herpes simplex viral infections, inflammatory diseases, corneal abrasions or injuries, and other systemic diseases.

Signs and Symptoms

The symptoms associated with corneal ulcers depend on whether they are infectious or sterile, as well as the aggressiveness of the infecting organism.

  • Red eye

  • Severe pain (not in all cases)

  • Tearing

  • Discharge

  • White spot on the cornea, that depending on the severity of the ulcer, may not be visible with the naked eye

  • Light sensitivity

Detection and Diagnosis

Corneal ulcers are diagnosed with a careful examination using a slit lamp microscope. Special types of eye drops containing dye such as fluorescein may be instilled to highlight the ulcer, making it easier to detect.

If an infectious organism is suspected, the eye care practitioner may order a culture. After numbing the eye with topical anaesthetic eye drops, cells are gently scraped from the corneal surface and tested to determine the infecting organism.


The course of treatment depends on whether the ulcer is sterile or infectious. Bacterial ulcers require aggressive treatment. In some cases, antibacterial eye drops are used every 15 minutes. Steroid medications are avoided in cases of infectious ulcers. Some patients with severe ulcers may require hospitalization for IV antibiotics and around-the-clock therapy. Sterile ulcers are typically treated by reducing the eye’s inflammatory response with steroid drops, anti-inflammatory drops, and antibiotics.

With acknowledgement to St. Lukes Eye Hospital.

Dacryocystitis is an infection of the tear sac that lies between the inner corner of the eyelids and the nose. It usually results from blockage of the duct that carries tears from the tear sac to the nose. The blocked duct harbours bacteria and becomes infected. Dacryocystitis may be acute (sudden onset) or chronic (frequently recurs). It may be related to a malformation of the tear duct, injury, eye infection, or trauma.

This problem is most common in infants because their tear ducts are often underdeveloped and clog easily. Babies often have recurrent episodes of infection; however, in most cases, the problem resolves as the child grows. In adults, the infection may originate from an injury or inflammation of the nasal passages. In many cases, however, the cause is unknown.

Signs and Symptoms

  • Generally affects one eye

  • Excessive tearing

  • Tenderness, redness, and swelling

  • Discharge

  • Red, inflamed bump on the inner corner of the lower lid

Detection and Diagnosis

During the examination, the eye care practitioner will determine the extent of the blockage. Cultures may be taken of the discharge to identify the type of infection. The eye care practitioner will also determine whether the infection has affected the eye.


The treatment for dacryocystitis is dependent on the person’s age, whether the problem is chronic or acute, and the cause of the infection.

Infants are usually treated first by gently massaging the area between the eye and nose to help open the obstruction along with antibiotic drops or ointments for the infection. Surgery may be necessary to clear the obstruction if medical treatment is not effective and the problem persists over several months.

Before surgery, the eye care practitioner may treat the child with antibiotics to make sure the infection is cleared. The operation is performed under general anaesthesia. The tear duct is gently probed to open the passage.

For adults, the eye care practitioner may clear the obstruction by irrigating the tear duct with saline. Surgery is sometimes necessary for adults if irrigation, or antibiotics fail to resolve the infection or if the infection becomes chronic. In these cases, dacryocystorhinostomy (DCR) is performed under general anaesthesia to create a new passage for the tear flow.

With acknowledgement to St. Lukes Eye Hospital.

Epi-retinal membrane (ERM) or macular pucker is a cellophane-like membrane that forms over the macula. It is typically a slow-progressing problem that affects the central vision by causing blur and distortion. As it progresses, the traction of the membrane on the macula may cause swelling.

ERM is seen most often in people over 75 years of age. It usually occurs for unknown reasons, but may be associated with certain eye problems such as: diabetic retinopathy, posterior vitreous detachment, retinal detachment, trauma, and many others.

Signs and Symptoms

  • Blurred vision
  • Double vision that is noticeable even with one eye covered
  • Distorted vision (straight lines may appear bent or wavy)

Detection and Diagnosis

The eye care practitioner is able to detect ERM with ophthalmoscopy during an examination of the retina. It has a glistening, cellophane-like appearance. The affect of ERM on the patient’s central vision is assessed with a visual acuity test and the Amsler Grid. If the eye care practitioner suspects macular swelling, he may order fluorescein angiography.


A procedure called a membrane peel is performed when vision has deteriorated to the point that it is impairing the patient’s lifestyle. Most vitreo-retinal surgeons recommend waiting for treatment until vision has decreased to the point that the risk of the procedure justifies the improvement.

The membrane peel is performed under local anaesthesia in an operating theatre. After making tiny incisions the membrane peel is often done in conjunction with a procedure called a vitrectomy.

With acknowledgement to St. Lukes Eye Hospital.

Anyone who has felt as if there was a grain of sand in his or her eye has probably had a foreign body. Foreign bodies might be superficial, or in more serious injuries, they may penetrate the eye. Fortunately, the cornea has such an incredible reflex tearing system that most superficial foreign bodies are naturally flushed out with our natural tears. But if the object is more deeply embedded, medical attention is required.

Signs and Symptoms

The symptoms of a foreign body may range from irritation to intense, excruciating pain. This is dependent on the location, material, and type of injury.

In rare situations where an object penetrates the eye, there may be few or no symptoms. If you have no symptoms, but suspect an object may have penetrated your eye, it’s always best to seek medical attention. The entry point of an intraocular foreign body is sometimes nearly invisible. Depending on their location, foreign bodies inside the eye may or may not cause pain or decreased vision.

foreign body
  • Mild to extreme irritation
  • Scratching
  • Burning
  • Soreness
  • Intense pain
  • Redness
  • Tearing
  • Light sensitivity
  • Decreased vision
  • Difficulty opening the eye

Detection and Diagnosis

The evaluation includes vision testing along with careful examination of the surface of the eye with a slit lamp microscope. When a superficial foreign body is suspected, the upper lid should be gently turned up to check underneath for trapped particles. If the foreign body is difficult to see even with a microscope, the eye care practitioner may instill a drop of fluorescein dye to highlight the area.

An examination inside the eye with ophthalmoscopy may also be indicated depending on the severity of the injury.


If a foreign object becomes embedded within the cornea, conjunctiva, or sclera, a medical professional must remove it.Attempting to remove it yourself is dangerous and could result in a permanent scar that could affect your vision.

Superficial foreign bodies are usually treated in the office. After numbing the eye with topical anaesthetic, the particle is carefully removed using a microscope. Afterward, antibiotic medications are generally prescribed to prevent infection. In some cases, foreign bodies become trapped underneath the eyelid. It is extremely important to examine under the eyelid for any remnant particles.

Intraocular foreign bodies typically must be removed in the operating theatre using a microscope and special instruments designed for working inside the eye. These injuries are often vision threatening and should be treated quickly.

Wearing appropriate safety glasses is the best way to prevent this type of injury. Protecting the eyes is especially important when working with machinery that could cause chips of wood or metal to splinter, as well as lawn equipment such as hedge and line trimmers.

If a particle of wood, glass, metal or any other foreign substance becomes trapped in your eye, here are some tips:

  1. Do not touch or rub your eye! This can embed the object more deeply, making it more difficult to remove.
  2. Keep your eye closed as much as possible. Blinking only increases the irritation.
  3. Do not try to remove the object yourself. This is very dangerous and may make the problem worse.
  4. Seek professional help immediately.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Histoplasmosis is caused by a fungus commonly found in certain dust and soil. It affects men and women equally.

histoplasmosisHistoplasmosis is contracted by inhaling dust that carries the fungal spores. Its effect on the body can vary widely in severity from one person to another. Many carriers have no symptoms at all, but those with mild exposure may experience flu-like symptoms and mild respiratory infections. Histoplasmosis is more likely to become a serious problem in people who already have a weakened immune system.

The fungus may affect the eye by causing small areas of inflammation and scarring of the retina. These are called “histo spots” and may be found in both eyes. Their effect on vision depends on the location of the scars. Scarring in the peripheral area of the retina may have little or no impact on vision, while a central scar affecting the macula may cause a prominent blind spot.

Most people with histo spots in the retina are totally unaware of their presence unless the central vision is affected. Studies indicate that only about 5% of those with histo spots are at risk of losing vision. Scientists have been unable find a link between the patients with minor histo spots and those who develop a severe loss of their central vision.

Signs and Symptoms

Many patients with histo spots in their eyes have no symptoms. Others may experience the following:

  • Distorted vision
  • Blind spots
  • Scars in the retina, ranging in severity

Detection and Diagnosis

Ocular histoplasmosis is detected with a dilated pupil examination of the retina using ophthalmoscopy. It is usually diagnosed based on its distinctive appearance and characteristics.


Ocular histoplasmosis usually requires no treatment except when abnormal blood vessels develop in the central retina. For these patients, laser treatment may be necessary. In some cases, surgical removal of the tiny, abnormal vessels has been successful.

Regular eye examinations and routine use of an Amsler Grid to monitor central vision is recommended for anyone with histo spots.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

The lens capsule is the thin, elastic-like bag that holds the intraocular lens (IOL) in position after cataract surgery.During the operation, the front (anterior) portion of the lens capsule is carefully opened and the cataract is removed.The IOL is inserted into the remaining (posterior) portion of the capsule. The remaining portion of the capsule becomes clouded in about 25% of cataract surgery patients.When this occurs, patients experience symptoms similar to those from the original cataract.

Signs and Symptoms

  • Gradual decrease of vision
  • Blurred vision
  • Glare from lights and sun

Detection and Diagnosis

The eye care practitioner can diagnose posterior capsule opacification during a routine eye examination using a slit lamp microscope. It is more easily detected if the pupils are dilated. Potential acuity testing is often performed to determine the expected improvement of vision.


A simple procedure called a YAG posterior capsulotomy is performed to restore vision lost from the clouded capsule. The YAG is a type of “cold” laser used to create a small opening in the center of the capsule, allowing a clear area for light to enter the eye. The procedure is painless, requires no anaesthesia, and has very little risk since no incision is required.

After the dilating drops wear off from the procedure, most patients notice an immediate improvement in vision. The improvement each person experiences is dependent on the extent of the capsular clouding and the overall eye health.

With acknowledgement to St. Lukes Eye Hospital.

Scleritis is an inflammatory disease that affects the conjunctiva, sclera, and episclera (the connective tissue between the conjunctiva and sclera). It is associated with underlying systemic disease in about half of the cases. The diagnosis of scleritis may lead to the detection of underlying systemic disease. Rarely, scleritis is associated with an infectious problem.

The affected area of the sclera may be confined to small nodules, or it may cause generalized inflammation. Necrotizing scleritis, a more rare, serious type, causes thinning of the sclera. Severe cases of scleritis may also involve inflammation of other ocular tissues.

Scleritis affects women more frequently then men. It most frequently occurs in those who are in their 40’s and 50’s. The problem is usually confined to one eye, but may affect both.

Signs and Symptoms

  • Severe, boring pain that can awaken the patient
  • Local or general redness of the sclera and conjunctiva
  • Extreme tenderness
  • Light sensitivity and tearing (in some cases)
  • Decreased vision (if other ocular tissues are involved)

Detection and Diagnosis

Along with visual acuity testing, measurement of intraocular pressure, slit lamp examination, and ophthalmoscopy, the eye care practitioner may request a physician to order blood tests to rule out diseases affecting the body. If involvement of the back of the eye is suspected, the physician may order imaging tests such as CT Scan, MRI, or ultrasonography of the eye.


Scleritis is treated with oral steroid and non-steroidal anti-inflammatory medication to reduce inflammation. Eye drops alone do not provide adequate treatment. In very severe cases of necrotizing scleritis, surgery may be required to graft scleral or corneal tissue over the area of thinned sclera.

With acknowledgement to St. Lukes Eye Hospital.

Amblyopia is a term used to describe an uncorrectable loss of vision in an eye that appears to be normal. It’s commonly referred to as “lazy eye” and can occur for a variety of reasons.

A child’s visual system is fully developed between approximately the ages of 9-11. Until then, children readily adapt to visual problems by suppressing or blocking out an image. If caught early, the problem can often be corrected and the vision preserved. However, after about age 11, it is difficult if not impossible to train the brain to use the eye normally.

Some causes of amblyopia include: strabismus (crossed or turned eye), congenital cataracts, cloudy cornea, droopy eyelid, unequal vision and uncorrected nearsightedness, farsightedness or astigmatism. Amblyopia may occur in various degrees depending on the severity of the underlying problem. Some patients just experience a partial loss; others are only able to recognize motion.

Patients with amblyopia lack binocular vision, or stereopsis – the ability to blend the images of both eyes together. Stereopsis is what allows us to appreciate depth. Without it, the ability to judge distance is impaired.

Signs and Symptoms

  • Poor vision in one or both eyes
  • Squinting or closing one eye while reading or watching television
  • Crossed or turned eye
  • Turning or tilting the head when looking at an object
  • Note: Children rarely complain of poor vision. They are able to adapt very easily to most visual impairments. Parents must be very observant of young children and should have a routine eye exam performed by the age of 2-3 to detect potential problems.

Detection and Diagnosis

When amblyopia is suspected, the optometrist will evaluate the following: vision, eye alignment, eye movements, and fusion (the brain’s ability to blend two images into a single image).


The treatment for amblyopia depends on the underlying problem. In some cases, the strong eye is temporarily patched so the child is forced to use the weaker eye. For children with problems relating to a refractive error, glasses may be necessary to correct vision. Problems that impair vision such as cataracts or droopy eyelids often require surgery. Regardless of the treatment required, it is of utmost importance that intervention is implemented as early as possible before the child’s brain learns to permanently suppress or ignore the eye.

With acknowledgement to St. Lukes Eye Hospital.

A retinal artery occlusion occurs when the central retinal artery or one of the arteries that branch off it becomes blocked. This blockage is typically caused by a tiny embolus (blood clot) in the blood stream. The occlusion decreases the oxygen supply to the area of the retina nourished by the affected artery, causing permanent vision loss.


In this photograph, the affected area of the retina is the pale, whitish-yellow region (blue arrow) that is normally supplied by the blocked artery. The surrounding reddish-orange area is healthy retina tissue.

Signs and Symptoms

• Transient loss of vision prior to the artery occlusion (in some cases).

Central artery occlusion

• Sudden, painless and complete loss of vision in one eye.

Branch artery occlusion

• Sudden, painless, partial loss of vision in one eye.

Detection and Diagnosis

Artery occlusion is diagnosed by examining the retina with an ophthalmoscope.


Unfortunately, there is no treatment that can consistently restore vision lost from an artery occlusion. However, if it is caught within the first hour and treatment is initiated immediately, recovery is possible in rare cases.

The following conditions increase the risk of problems that may affect the vessels of the eye:

  • High cholesterol
  • Heart disease
  • Arteriosclerosis
  • Hypertension
  • Diabetes
  • Glaucoma

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Blepharitis is a common inflammatory condition that affects the eyelids. It usually causes burning, itching and irritation of the lids. In severe cases, it may also cause styes, irritation and inflammation of the cornea (keratitis) and conjunctiva (conjunctivitis). Some patients have no symptoms at all.

Blepharitis is usually a chronic problem that can be controlled with extra attention to lid hygiene. However, it is sometimes caused by an infection and may require medication.

Signs and Symptoms

  • Sandy, itchy eyes
  • Red and/or swollen eyelids
  • Crusty, flaky skin on the eyelids
  • Dandruff

Detection and Diagnosis

Blepharitis is detected during a routine examination of the eyelids and lashes using a slit lamp microscope.


The key to controlling blepharitis is to keep the eyelids and eyelashes clean. Begin by soaking a clean washcloth in hot tap water. Hold the washcloth to your cheek to test for temperature before placing it on the eyes. Place the compress on closed eyelids for five minutes, and then repeat. Next, gently scrub the eyelids with a washcloth or cotton swab soaked in a mixture of equal parts of baby shampoo and water. Afterward, rinse the lids thoroughly with warm water.

This treatment should be repeated two to three times daily for two weeks, and then reduced to once daily. Consult your eye care practitioner regarding the correct medical treatment. In some cases, anti-inflammatory and antibiotic drops or ointments are necessary for flare-ups or more severe cases.

With acknowledgement to St. Lukes Eye Hospital.

When cataracts are mentioned, people often think of a film that grows on their eyes causing them to see double or blurred images. However, a cataract does not form on the eye, but rather within the eye.

cat none


Eye without a cataract

Eye with a cataract

A cataract is a clouding of the natural lens, the part of the eye responsible for focusing light and producing clear, sharp images. The lens is contained in a sealed bag or capsule. As old cells die they become trapped within the capsule. Over time, the cells accumulate causing the lens to cloud, making images look blurred or fuzzy. For most people, cataracts are a natural result of aging.

In fact, they are the leading cause of visual loss among adults 55 and older. Eye injuries, certain medications, and diseases such as diabetes and alcoholism have also been known to cause cataracts.

eye emmetrop


Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Central serous chorioretinopathy (CSCR) is a problem that affects the macula (central portion of the retina). The exact cause is not understood. CSCR occurs when a small break forms in the pigment layer of the retina. Fluid from the layer of blood vessels that lie underneath the retina seeps up through the break, causing a small detachment to form under the retina.

This problem is somewhat similar to a water blister that forms on the skin. The process is similar to CSCR: fluid collects beneath the skin’s surface, causing the layers of skin to separate.

CSCR affects men more often then women and usually occurs between the ages of 25 and 50. Stress is thought to be linked to this problem. CSCR typically resolves spontaneously, but it can recur. In some cases, it may lead to moderate but permanent loss of central vision.

Signs and Symptoms

  • Blurred central vision
  • Wavy, distorted vision
  • Central blind spot

Detection and Diagnosis

Usually the eye care practitioner can diagnose CSCR with an examination of the retina using ophthalmoscopy. In most cases fluorescein angiography is used to gather additional information about the extent and severity of the problem.


Most patients with CSCR do not require treatment. The fluid usually absorbs gradually over a period of months. Occasionally, steroid and non-steroidal anti-inflammatory eye drops are prescribed. In cases where visual recovery is delayed, laser treatment may be required to seal the leak and help the vision improve.

With acknowledgement to St. Lukes Eye Hospital.

A chalazion (stye) is a small lump in the eyelid caused by obstruction of an oil producing or meibomian gland. Chalazia may occur in the upper or lower lids, causing redness, swelling and soreness in some cases.


Signs and Symptoms

  • Raised, swollen bump on the upper or lower eye lid
  • Often red
  • May be tender and sore

Detection and Diagnosis

Patients often request an examination after an episode of pain and swelling of the lid. The eye care practitioner can make the diagnosis during a simple examination of the eyelids.


In the early stages, chalazia may be treated at home with the repeated use of warm compresses for 15 – 20 minutes followed by several minutes of light lid massage. This helps to reduce the swelling and makes the lid more comfortable. However, if the chalazion does not diminish or recurs, medical attention may be necessary. This may include draining the chalazion along with the use of antibiotic and anti-inflammatory medications.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Know How to Treat a Chemical Burn?

Quick reactions can make the difference between sight and blindness

It can happen in the blink of an eye. While pouring liquid drain cleaner down a sink, some of the chemical splashes up in your face, hitting you squarely in the eye. Chemical injuries don’t just happen in the workplace. Most homes have dozens of everyday products that pose tremendous danger to vision if they contact the eye.

The severity of the injury is related to whether the chemical is alkali or acid-based. Alkali chemicals are more destructive then acidic chemicals because of their ability to adhere to the eye and penetrate tissues. However, acid burns may be compounded by glass injuries caused by an explosion.

Alkali- based chemicals

  • Lime (cement, plaster, whitewash)

  • Drain cleaners

  • Lye

  • Metal polishes

  • Ammonia

  • Oven cleaners

Acid-based chemicals

  • Swimming pool acid (muriatic acid)

  • Battery (sulfuric) acid

Often, the difference between a serious but treatable injury and losing vision is a matter of understanding a few principles of ocular first aid.

Emergency care

First aid at home

  • Help the patient hold his or her head over a sink

  • Gently hold the lids apart with a cotton swab or dry cloth

  • Pour water over the eye, making sure to rinse inside the eyelids

  • Call your ophthalmologist

After chemical exposure, the first step is to immediately (within seconds) begin flushing the eye with water. If the accident occurs in an industrial setting, special irrigating facilities should be available. If the injury happens at home, begin flushing the eye with water right away, call for help immediately and contact your local ophthalmologist.

The easiest way to irrigate at home is for the patient to hold his or her head over a sink while the helper continuously pours water over the eye with a glass or cup.It is important to gently hold the lids apart while irrigating in order to rinse underneath the lids and wash away as much of the chemical as possible. Using a dry cloth is helpful because the lids are difficult to hold back when they are wet. Continue flushing the eye for approximately 20 minutes.

Secondary care at the ophthalmologist’s office

If possible, bring the chemical used at the time of the accident to the doctor’s office. The type of chemical, concentration, and key ingredients may give the doctor valuable information needed for treatment. The doctor may continue irrigation to insure that the chemical is diluted as much as possible. The eye will be carefully examined under magnification to determine the extent of the injury and whether there are any foreign particles imbedded in the eye.

An ounce of prevention…

Taking care to prevent chemical injuries is the best first aid. Follow these simple steps to reduce your risk:

  • Follow package directions and warnings before using chemicals

  • When using chemicals, always wear safety glasses

  • Never put your face over a drain after applying chemicals

The chance of regaining useful vision following a chemical accident is dependent on the nature and type of injury. However, knowing how to initiate treatment at home greatly increases the odds of recovery and saving vision.

With acknowledgement to St. Lukes Eye Hospital.

Choroidal neovascular membrane (CNVM) is a problem that is related to a wide variety of retinal diseases, but is most commonly linked to age-related macular degeneration. With CNVM, abnormal blood vessels stemming from the choroid (the blood vessel-rich tissue layer just beneath the retina) grow up through the retinal layers. Imagine the abnormal blood vessels as weeds creeping up through the cracks of a pavement. These new vessels are very fragile and break easily, causing blood and fluid to pool within the layers of the retina.

As the vessels leak, they disturb the delicate retinal tissue, causing the vision to deteriorate. The severity of the symptoms depends on the size of the CNVM and its proximity to the macula. Patients’ symptoms may be very mild such as a blurry or distorted area of vision, or more severe, like a central blind spot.


Signs and Symptoms

  • Blurred, grayed-out areas
  • Distorted vision
  • Central blind spot

Detection and Diagnosis

A simple vision test called an Amsler Grid should always be done first for patients who notice a problem with their central vision. This test provides the eye care practitioner with vital information about the location and severity of the problem. CNVM is usually difficult to diagnose by simply looking at the retina with an ophthalmoscope. A special dye test called a fluorescein angiogram is used to study the circulation of the retina and show areas of leaking blood vessels.


The appropriate treatment is dependent on several factors such as: size and location of the membrane and the amount of time that passed since the symptoms first began. If the CNVM is small, compact, and caught very early, a delicate surgery called a sub-foveal excision can be performed to remove it. This procedure has the most risk but also offers the patient the best possibility of visual improvement.

Laser photocoagulation, a procedure that seals leaking blood vessels, is the simplest and most common treatment for CNVM. It is reserved for patients with bleeding outside of the central retina because it creates a scar that affects the vision. Treating the retina with laser gives the surgeon the most control over placement and size of the scar. Allowing an undiagnosed leak to resolve on its own usually causes a much more devastating affect on the vision.

Unfortunately, for some patients, no treatment is appropriate. All patients with CNVM should monitor their vision with an Amsler Grid and report any changes to their eye care practitioner immediately.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Cogan’s Dystrophy is a disease that affects the cornea. It is commonly called Map-Dot-Fingerprint Dystrophy because of microscopic dot and fingerprint-like patterns that form within the layers of the cornea.


The cornea is comprised of five layers. Cogan’s affects the superficial cornea layer called the epithelium. The epithelium’s bottom, or basement layer of cells becomes thickened and uneven. This weakens the bond between the cells and sometimes causes the epithelium to become loosened and slough off in areas. This problem is called corneal erosion.

Even though this disease is commonly known as a dystrophy (a term that describes genetic diseases), Cogan’s is not necessarily an inherited problem. It often affects both eyes and is typically diagnosed after the age of 30. Cogan’s usually becomes progressively worse with age.

Signs and Symptoms

Some patients with Cogan’s dystrophy have no symptoms at all. The symptoms among patients may may vary widely in severity and include:

  • Light sensitivity

  • Glare

  • Fluctuating vision

  • Blurred vision

  • Irregular astigmatism (uneven corneal surface)

  • Mild to extreme irritation and discomfort that is worse in the morning

Detection and Diagnosis

The eye care practitioner examines the layers of the cornea with a slit lamp microscope. In some cases, corneal topography may be needed to evaluate and monitor astigmatism resulting from the disease.


The treatment for Cogan’s is dependent on the severity of the problem. The first step is to lubricate the cornea with artificial tears to keep the surface smooth and comfortable. Lubricating ointments are recommended at bedtime so the eyes are more comfortable in the morning. Salt solution drops or ointments such as sodium chloride are often prescribed to reduce swelling and improve vision.Gas permeable contact lenses are occasionally fitted for patients with irregular astigmatism to create a smooth, even corneal surface and improve vision.

For patients with recurrent corneal erosion, soft, bandage contact lenses may be used to keep the eye comfortable and allow the cornea to heal. In some cases, laser treatment may be beneficial. The surgeon removes the epithelium with an Excimer laser, creating a regular, smooth surface. The epithelium quickly regenerates, usually within a matter of days, forming a better bond with the underlying cell layer.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Colour blindness may be a hereditary condition or caused by disease of the optic nerve or retina. Acquired colour vision problems only affect the eye with the disease and may become progressively worse over time. Patients with a colour vision defect caused by disease usually have trouble discriminating blues and yellows.

Inherited colour blindness is most common, affects both eyes, and does not worsen over time. This type is found in about 8% of males and 0.4% of females. These colour problems are linked to the X chromosome and are almost always passed from a mother to her son.

Colour blindness may be partial (affecting only some colours), or complete (affecting all colours). Complete colour blindness is very rare. Those who are completely colour blind often have other serious eye problems as well.

Photoreceptors called cones allow us to appreciate colour. These are concentrated in the very centre of the retina and contain three photosensitive pigments: red, green and blue. Those with defective colour vision have a deficiency or absence in one or more of these pigments. Those with normal colour vision are referred to as trichromats. People with a deficiency in one of the pigments are called anomalous trichromats (the most common type of colour vision problem.) A dichromat has a complete absence in one cone pigment.

Signs and Symptoms

The symptoms of colour blindness are dependent on several factors, such as whether the problem is congenital, acquired, partial, or complete.

  • Difficulty distinguishing reds and greens (most common)

  • Difficulty distinguishing blues and greens (less common)

The symptoms of more serious inherited colour vision problems and some acquired types’ problems may include:

  • Objects appear as various shades of gray (this occurs with complete colour blindness and is very rare)

  • Reduced vision

  • Nystagmus

Detection and Diagnosis

Colour vision deficiency is most commonly detected with special coloured charts called the Ishihara Test Plates. On each plate is a number composed of coloured dots. While holding the chart under good lighting, the patient is asked to identify the number. Once the colour defect is identified, more detailed colour vision tests may be performed.


There is no treatment or cure for colour blindness. Those with mild colour deficiencies learn to associate colours with certain objects and are usually able to identify colour as everyone else does. However, they are unable to appreciate colour in the same way as those with normal colour vision.

With acknowledgement to St. Lukes Eye Hospital.

Computer vision syndrome (CVS) is a term that describes eye-related problems and the other symptoms caused by prolonged computer use. As our dependence on computers continues to grow, an increasing number of people are seeking medical attention for eye strain and irritation, along with back, neck, shoulder, and wrist soreness.


Magnified view of a printed letter

A pix

Magnified view of a letter on a computer screen

These problems are more noticeable with computer tasks than other near work because letters on the screen are formed by tiny dots called pixels, rather than a solid image. This causes the eye to work a bit harder to keep the images in focus.

There is no scientific evidence that computer screens are harmful to the eyes. A common myth is that eye strain caused by reading and close work is damaging to the eyes. This is not true; however, those who work at computers often experience many frustrating symptoms.

Signs and Symptoms

  • Blurred near vision
  • Difficulty focusing from close to far and back again
  • Sore, irritated eyes
  • Dry eyes
  • Red eyes
  • Eye fatigue
  • Headaches that disappear after a period of rest
  • Irritation and discomfort while wearing contact lenses
  • Soreness and pain in the neck, shoulder, and back

Detection and Diagnosis

Your eye care practitioner will perform a complete eye examination that includes: near and distance visual acuity, refraction, tonometry, and an examination of the eye structures with a slit lamp microscope and ophthalmoscopy.

It is important to provide the eye care practitioner with detail about your work environment, work habits, and detail about the symptoms and their patterns. Bring your prescription glasses with you so the eye care practitioner can determine if they are appropriate for computer work.


The three main areas that should be addressed when treating CVS patients are: eye-related problems, work environment, and posture.

Eye-related problems

  • Make sure the glasses are the correct prescription and designed for working at a computer. Patients who wear bifocals may find themselves keeping their head in an uncomfortable position in order to see the screen. Your optometrist will determine the glasses best suited for the task, and if necessary, prescribe glasses with an adjusted bifocal height and width.

  • Blink frequently and instill artificial tears as needed. One of the biggest complaints of patients with CVS is dry, irritated, red eyes. This is common because we tend to blink less when reading.

  • Stop periodically and look away from the computer screen. Looking up relaxes the eye’s focusing mechanism and reduces the problem of eye strain.

Work environment

cvsposture incorrect

Incorrect hand position

cvsposture correct
Correct hand position
  • Sit approximately 24″ from the monitor. Sitting at the appropriate working distance from the computer screen maximizes the clarity of the text and images.

  • Adjust the monitor so the centre is slightly below eye level. This keeps the neck in the most natural position and reduces soreness and fatigue.

  • Minimize glare on the screen. Arrange the lighting and desk to eliminate glare on the monitor. An anti-reflective screen placed over the monitor is sometimes helpful.

Posture and work habits

  • Maintain good posture. Sitting up straight with your feet on the floor can reduce back stress. Use a cushion for the lower back if necessary.

  • Keep your wrists straight when typing. Avoid resting your wrists on the keyboard.

  • Place the mouse and keyboard at the same level, keeping them close to the body. The keyboard level should at a slightly lower level than the desk.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Conjunctivitis, commonly known as pink eye, is an infection of the conjunctiva (the outer-most layer of the eye that covers the sclera).


The three most common types of conjunctivitis are: viral, allergic, and bacterial. Each requires different treatments. With the exception of the allergic type, conjunctivitis is typically contagious.

The viral type is often associated with an upper respiratory tract infection, cold, or sore throat. The allergic type occurs more frequently among those with allergic conditions.When related to allergies, the symptoms are often seasonal. Allergic conjunctivitis may also be caused by intolerance to substances such as cosmetics, perfume, or drugs.Bacterial conjunctivitis is often caused by bacteria such as staphylococcus and streptococcus. The severity of the infection depends on the type of bacteria involved.

Signs and Symptoms

Viral conjunctivitis

  • Watery discharge
  • Irritation
  • Red eye
  • Infection usually begins with one eye, but may spread easily to the other eye

Allergic conjunctivitis

  • Usually affects both eyes
  • Itching
  • Tearing
  • Swollen eyelids

Bacterial conjunctivitis

  • Stringy discharge that may cause the lids to stick together, especially after sleeping
  • Swelling of theconjunctiva
  • Redness
  • Tearing
  • Irritation and/or a gritty feeling
  • Usually affects only one eye, but may spread easily to the other eye

Detection and Diagnosis

Conjunctivitis is diagnosed during a routine eye exam using a slit lamp microscope. In some cases, cultures are taken to determine the type of bacteria causing the infection.


The appropriate treatment depends on the cause of the problem.

For the allergic type, cool compresses and artificial tears sometimes relieve discomfort in mild cases. In more severe cases, non-steroidal anti-inflammatory medications and antihistamines may be prescribed. Some patients with persistent allergic conjunctivitis may also require topical steroid drops.

Bacterial conjunctivitis is usually treated with antibiotic eye drops or ointments that cover a broad range of bacteria.

Like the common cold, there is no cure for viral conjunctivitis; however, the symptoms can be relieved with cool compresses and artificial tears (found in most pharmacies). For the worst cases, topical steroid drops may be prescribed to reduce the discomfort from inflammation. Viral conjunctivitis usually resolves within 3 weeks.

To avoid spreading infection, take these simple steps:

  • Disinfect surfaces such as doorknobs and counters with diluted bleach solution
  • Don’t swim (some bacteria can be spread in the water)
  • Avoid touching the face
  • Wash hands frequently
  • Don’t share towels or washcloths
  • Do not reuse handkerchiefs (using a tissue is best)
  • Avoid shaking hands

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

cme w inset

In this retinal photograph, the swelling is the yellowish spots (arrow) in the macula.

Cystoid macular oedema (CME), or swelling of the macula, typically occurs as a result of disease, injury or more rarely, eye surgery. Fluid collects within the layers of the macula, causing blurred, distorted central vision. CME rarely causes a permanent loss of vision, but the recovery is often a slow, gradual process. The majority of patients recover in 2 to 15 months.

Signs and Symptoms

  • Blurred central vision
  • Distorted vision (straight lines may appear wavy)
  • Vision is tinted pink
  • Light sensitivity

Detection and Diagnosis

It is very difficult to detect CME during a routine examination. A diagnosis is often based on the patient’s symptoms and a special dye test called a fluorescein angiogram (FA).


The first line of treatment for CME is usually anti-inflammatory drops. In certain cases, medication is injected near the back of the eye for a more concentrated effect. Oral medications are sometimes prescribed to reduce the swelling.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.


The cytomegalovirus (CMV) is related to the herpes virus and is present in almost everyone. Normally, most people’s immune systems are able to fight the virus, preventing it from causing problems in their bodies. However, when the immune system is suppressed because of disease (HIV), organ or bone marrow transplant, or chemotherapy, the CMV virus can cause damage and disease to the eye and the rest of the body.

CMV is the most common type of virus that infects those who are HIV positive. It affects the eye in about 30% of the cases by causing damage to the retina. This is called CMV retinitis. The likelihood of developing CMV retinitis increases as the CD4 cell count decreases.

CMV retinitis may affect one eye at first, but usually progresses to both eyes and becomes worse as the patient’s ability to fight infection decreases. The virus is sight threatening and usually requires the care and treatment of a vitreo-retinal surgeon.Patients with CMV retinitis are at risk of retinal detachment, haemorrhages, and inflammation of the retina that can lead to permanent loss of vision and even blindness.

Signs and Symptoms

CMV retinitis usually causes symptoms, but not always.Patients with a condition that suppresses the immune system should watch for the following eye symptoms while under the care of a physician.

  • Floaters (spots, bugs, spider webs)
  • Light flashes
  • Blind spots
  • Blurred vision
  • Obstructed areas of vision
  • Sudden decrease of vision

Detection and Diagnosis

Most patients with CMV retinitis are referred for eye treatment by another physician. The vitreo-retinal surgeon diagnoses CMV retinitis by thoroughly examining the back of the eye using ophthalmoscopy. Fluorescein angiography may be needed to evaluate the circulatory system of the retina.


When managing CMV retinitis, the doctor’s goal is to slow the progression of the disease and to treat related eye problems. Anti-viral medications such as ganciclovir or foscarnet are often prescribed. These drugs can be administered orally, intravenously, injected directly into the eye or through an intravitreal implant.


Photographs of retinas affected with CMV retinitis.


Normal (unaffected) retina

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Diabetes is a disease that occurs when the pancreas does not secrete enough insulin or the body is unable to process it properly. Insulin is the hormone that regulates the level of sugar (glucose) in the blood. Diabetes can affect children and adults.


How does diabetes affect the retina?

Patients with diabetes are more likely to develop eye problems such as cataracts and glaucoma, but the disease’s effect on the retina is the main threat to vision. Most patients develop diabetic changes in the retina after approximately 20 years. The effect of diabetes on the eye is called diabetic retinopathy.

Over time, diabetes affects the circulatory system of the retina. The earliest phase of the disease is known as background diabetic retinopathy. In this phase, the arteries in the retina become weakened and leak, forming small, dot-like haemorrhages. These leaking vessels often lead to swelling or oedema in the retina and decreased vision.

The next stage is known as proliferative diabetic retinopathy. In this stage, circulation problems cause areas of the retina to become oxygen-deprived or ischaemic. New, fragile, vessels develop as the circulatory system attempts to maintain adequate oxygen levels within the retina. This is called neovascularization. Unfortunately, these delicate vessels haemorrhage easily. Blood may leak into the retina and vitreous, causing spots or floaters, along with decreased vision.

In the later phases of the disease, continued abnormal vessel growth and scar tissue may cause serious problems such as retinal detachment.

Signs and Symptoms

The effect of diabetic retinopathy on vision varies widely, depending on the stage of the disease. Some common symptoms of diabetic retinopathy are listed below, however, diabetes may cause other eye symptoms.

  • Blurred vision (this is often linked to blood sugar levels)
  • Floaters and flashes
  • Sudden loss of vision

Detection and Diagnosis

Diabetic patients require routine eye examinations so related eye problems can be detected and treated as early as possible. Most diabetic patients are frequently examined by an internist or endocrinologist who in turn work closely with the eye care practitioner.

The diagnosis of diabetic retinopathy is made following a detailed examination of the retina with an ophthalmoscope. Most patients with diabetic retinopathy are referred to vitreo-retinal surgeons who specialize in treating this disease.


Diabetic retinopathy is treated in many ways depending on the stage of the disease and the specific problem that requires attention. The retinal surgeon relies on several tests to monitor the progression of the disease and to make decisions for the appropriate treatment. These include: fluorescein angiography, retinal photography, and ultrasound imaging of the eye.

The abnormal growth of tiny blood vessels and the associated complication of bleeding is one of the most common problems treated by vitreo-retinal surgeons. Laser surgery called pan retinal photocoagulation (PRP) is usually the treatment of choice for this problem.

With PRP, the surgeon uses laser to destroy oxygen-deprived retinal tissue outside of the patient’s central vision. While this creates blind spots in the peripheral vision, PRP prevents the continued growth of the fragile vessels and seals the leaking ones. The goal of the treatment is to arrest the progression of the disease.

Vitrectomy is another surgery commonly needed for diabetic patients who suffer a vitreous haemorrhage (bleeding in the gel-like substance that fills the centre of the eye). During a vitrectomy, the retina surgeon carefully removes blood and vitreous from the eye, and replaces it with clear salt solution (saline). At the same time, the surgeon may also gently cut strands of vitreous attached to the retina that create traction and could lead to retinal detachment or tears.

Patients with diabetes are at greater risk of developing retinal tears and detachment. Tears are often sealed with laser surgery. Retinal detachment requires surgical treatment to reattach the retina to the back of the eye. The prognosis for visual recovery is dependent on the severity of the detachment.


Researchers have found that diabetic patients who are able to maintain appropriate blood sugar levels have fewer eye problems than those with poor control. Diet and exercise play important roles in the overall health of those with diabetes.

Diabetics can also greatly reduce the possibilities of eye complications by scheduling routine examinations with an eye care practitioner. Many problems can be treated with much greater success when caught early.

With acknowledgement to St. Lukes Eye Hospital.

Dry eye syndrome is one of the most common problems treated by eye care practitioners. Millions of people worldwide suffer from dry eyes. It is usually caused by a problem with the quality of the tear film that lubricates the eyes.

Tears are comprised of three layers. The mucous layer coats the cornea, the eye’s clear outer window, forming a foundation so the tear film can adhere to the eye. The middle aqueous layer provides moisture and supplies oxygen and other important nutrients to the cornea. This layer is made up of 98 percent water along with small amounts of salt, proteins and other compounds. The outer lipid layer is an oily film that seals the tear film on the eye and helps to prevent evaporation.

Tears are formed in several glands around the eye. The water layer is produced in the lacrimal gland, located under the upper eyelid. Several smaller glands in the lids make the oil and mucous layers. With each blink, the eyelids spread the tears over the eye. Excess tears flow into two tiny drainage ducts in the corner of the eye by the nose. These ducts lead to tiny canals that connect to the nasal passage. The connection between the tear ducts and the nasal passage is the reason that crying causes a runny nose.

In addition to lubricating the eye, tears are also produced as a reflex response to outside stimuli such as injury or emotion. However, reflex tears do little to soothe a dry eye, which is why someone with watery eyes may still complain of irritation.

Dry eye syndrome has many causes. One of the most common reasons for dryness is simply the normal aging process. As we grow older, our bodies produce less oil – 60% less at age 65 then at age 18. This is more pronounced in women, who tend to have drier skin then men. The oil deficiency also affects the tear film. Without as much oil to seal the watery layer, the tear film evaporates much faster, leaving dry areas on the cornea.

Many other factors, such as hot, dry or windy climates, high altitudes, air-conditioning and cigarette smoke also cause dry eyes. Many people also find their eyes become irritated when reading or working on a computer. Stopping periodically to rest and blink keeps the eyes more comfortable.

Contact lens wearers may also suffer from dryness because the contact lenses absorb the tear film, causing proteins to form on the surface of the lens. Certain medications, thyroid conditions, vitamin A deficiency, and diseases such as Parkinson’s and Sjogren’s can also cause dryness. Women frequently experience problems with dry eyes as they enter menopause because of hormonal changes.

Signs and Symptoms

punctal plugs

  • Itching
  • Burning
  • Irritation
  • Redness
  • Blurred vision that improves with blinking
  • Excessive tearing
  • Increased discomfort after periods of reading, watching TV, or working on a computer

Detection and Diagnosis

There are several methods to test for dry eyes. The eye care practitioner will first determine the underlying cause by measuring the production, evaporation rate and quality of the tear film. Special drops that highlight problems that would be otherwise invisible are particularly helpful to diagnose the presence and extent of the dryness.


When it comes to treating dry eyes, everyone’s needs are a little different. Many find relief simply from using artificial tears on a regular basis. Some of these products are watery and alleviate the symptoms temporarily; others are thicker and adhere to the eye longer. Preservative-free tears are recommended because they are the most soothing and have fewer additives that could potentially irritate. Avoid products that whiten the eyes – they don’t have adequate lubricating qualities and often make the problem worse.

Closing the opening of the tear drain in the eyelid with special inserts called punctal plugs is another option. This works like closing a sink drain with a stopper. These special plugs trap the tears on the eye, keeping it moist. This may be done on a temporary basis with a dissolvable collagen plug, or permanently with a silicone plug.

There are also simple lifestyle changes that can significantly improve irritation from dry eyes. For example, drinking eight to ten glasses of water each day keeps the body hydrated and flushes impurities. Make a conscious effort to blink frequently – especially when reading or watching television. Avoid rubbing the eyes. This only worsens the irritation.

Treating dry eye problems is important not only for comfort, but also for the health of the cornea.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Patients with ectropion have a sagging lower eyelid that leaves the eye exposed and dry. It is caused by a lack of tone of the delicate muscles that hold the lid taut against the eye. Excessive tearing is common with ectropion, but wiping the tears away only causes the lid to sag more. Ectropion is most common among people over the age of 60.

Signs and Symptoms


  • Irritation
  • Burning
  • Gritty, sandy feeling
  • Excessive tearing
  • Red, irritated eyelid

Detection and Diagnosis

Ectropion can be diagnosed with a routine eye examination.


The irritation can be temporarily relieved with artificial tears and ointments to lubricate the eye; however, surgery to tighten the lid is usually necessary to correct this problem.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.


Entropion, an eyelid that turns inward, is a problem that typically affects the lower lid. It usually stems from a muscle spasm; however, it can also be caused by scarring from trauma or inflammation from certain diseases that involve the eyelids.

When the eyelid turns inward, the lashes rub against the eye, resulting in irritation, scratchiness, tearing and redness. Surgery is often required to correct the problem.

Signs and Symptoms
  • Tearing

  • Burning

  • Irritation

  • Sandy, gritty feeling

  • Red eye

Detection and Diagnosis

Entropion can be detected during a routine eye examination. A slit lamp microscope is used to examine the effects of the in-turned eyelashes on the surface of the eye.


The most effective treatment for entropion is surgery, although some patients find temporary relief by pulling the lower lid down with a piece of tape. Artificial tears are also helpful to ease the irritation caused from the lashes rubbing against the eye.

Episcleritis is an inflammatory condition of the connective tissue between the conjunctiva and sclera, known as the episclera. The eye’s red appearance makes it look similar to conjunctivitis, or pink eye, but there is no discharge or tearing. It usually has no apparent cause; however, it is sometimes associated with systemic inflammatory conditions such as arthritis, lupus, and inflammatory bowel disease. Rosacea, herpes simplex, gout, tuberculosis, and other diseases are also occasionally underlying causes.

Women are typically affected by episcleritis more frequently than men. It characteristically occurs in people who are in their 30’s and 40’s and is often a recurrent problem.

Signs and Symptoms

  • Generalized or local redness.
  • Mild soreness or discomfort.

Detection and Diagnosis

Episcleritis is diagnosed with a slit lamp examination. The eye care practitioner will look for discharge, pain, and involvement of the underlying sclera to rule out other problems.


Treatment for episcleritis is usually not needed. Chilled artificial tears can be used to soothe the eye and reduce mild inflammation. In more severe cases of episcleritis, mild steroids and anti-inflammatory medications are prescribed to reduce inflammation.

With acknowledgement to St. Lukes Eye Hospital.

The space between the crystalline lens and the retina is filled with a clear, gel-like substance called vitreous. In a newborn, the vitreous has an egg-white consistency and is firmly attached to the retina. With age, the vitreous thins and may separate from the back of the eye. This is called posterior vitreous detachment (PVD), a very common, usually harmless condition.

As the vitreous pulls free from the retina, it is often accompanied by light flashes or floaters. Floaters are caused by tiny bits of vitreous gel or cells that cast shadows on the retina. Flashes occur when the vitreous tugs on the sensitive retinal tissue.

There are other more serious causes of flashes and floaters, however. Retinal tears, retinal detachment, infection, inflammation, haemorrhage, or an injury such as a blow to the head may also cause floaters and flashes. (Have you ever seen stars after bumping your head?) Occasionally, flashes of light are caused by neurological problems such as a migraine headache. When related to a headache, the flashes of light are seen in both eyes and usually lasts 20-30 minutes before the headache starts.

Signs and Symptoms

  • Black spots or “spider webs” that seem to float in the vision in a cluster or alone
  • Spots that move or remain suspended in one place
  • Flickering or flashing lights that are most prominent when looking at a bright background like a clear, blue sky

Symptoms that may indicate a more serious problem

  • Sudden decrease of vision along with flashes and floaters
  • Veil or curtain that obstructs part or all of the vision
  • Sudden increase in the number of floaters

Detection and Diagnosis

Notify your eye care practitioner immediately if you notice a sudden shower of floaters, new light flashes, a veil or curtain obstructing your vision, or any other change. The eye care practitioner will dilate your pupils with drops and examine the vitreous and retina inside the eye with an ophthalmoscope.


Because of the risk, surgery is rarely indicated for PVD except when the floaters obscure the vision. In these cases, surgical removal of the vitreous (vitrectomy) may be considered only if the vision is significantly affected. This treatment is rarely needed since floaters typically become less bothersome over a period of weeks to months as they settle below the line of sight.

If the flashes and floaters are related to a problem other than a PVD, surgical treatment may be required.

Be proactive and monitor your vision

It is important to periodically assess the vision of each eye. Many problems can be detected early by simply comparing both eyes.

To test your vision:

  1. Cover one eye and pick a point to look at straight ahead
  2. Note the quality of your central and peripheral vision, noting any change
  3. Look for any obstructions, veils or curtains in your peripheral vision
  4. Watch for floaters, flashes
  5. Note the duration and intensity of the symptoms
  6. Cover fellow eye and repeat

Report any new symptoms or changes in vision to your eye care practitioner.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

The fovea (arrow) is the center most part of the macula.

This tiny area is responsible for our central, sharpest vision. A healthy fovea is the key for reading, watching television, driving, and other activities that require the ability to see detail. Unlike the peripheral retina, it has no blood vessels. Instead, it has a very high concentration of cones (photoreceptors responsible for color vision), allowing us to appreciate colour.



Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Fuchs’ dystrophy is an inherited condition that affects the delicate inner layer (endothelium) of the cornea. The endothelium functions as a pump mechanism, constantly removing fluids from the cornea to maintain its clarity. Patients gradually lose these endothelial cells as the dystrophy progresses. Once lost, the endothelial cells do not grow back, but instead spread out to fill the empty spaces. The pump system becomes less efficient, causing corneal clouding, swelling and eventually, reduced vision.

In the early stages, Fuchs’ patients notice glare and light sensitivity. As the dystrophy progresses, the vision may seem blurred in the morning and sharper later in the day. This happens because the internal layers of the cornea tend to retain more moisture during sleep, that evaporates when the eyes are open. As the dystrophy worsens, the vision becomes continuously blurred.

Fuchs’ affects both eyes and is slightly more common among women than men. It generally begins at 30-40 years of age and gradually progresses. If the vision becomes significantly impaired, a corneal transplant may be indicated. Sometimes corneal transplant (also known as penetrating keratoplasty or PKP) is performed along with cataract and intraocular lens implant surgery.

Signs and Symptoms

  • Hazy vision that is often most pronounced in the morning
  • Fluctuating vision
  • Glare when looking at lights
  • Light sensitivity
  • Sandy, gritty sensation

Detection and Diagnosis

Fuchs’ is detected by examining the cornea with a slit lamp microscope that magnifies the endothelial cells thousands of times. The health of the endothelium is evaluated and monitored with pachymetry and specular microscopy.



Fuchs’ cannot be cured; however, with certain medications, blurred vision resulting from the corneal swelling can be controlled. Salt solutions such as sodium chloride drops or ointment are often prescribed to draw fluid from the cornea and reduce swelling. Another simple technique that reduces moisture in the cornea is to hold a hair dryer at arm’s length, blowing air into the face with the eyes closed. This technique draws moisture from the cornea, temporarily decreases swelling, and improves the vision.

Corneal transplant is indicated when the vision deteriorates to the point that it impairs the patient’s ability to function normally.

This is a highly magnified photo of the layers of the cornea. The “oedema” caused by Fuchs’ can be seen as the mottled appearance.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Glaucoma is a disease caused by increased intraocular pressure (IOP) resulting either from a malformation or malfunction of the eye’s drainage structures. Left untreated, an elevated IOP causes irreversible damage to the optic nerve and retinal fibres resulting in a progressive, permanent loss of vision. However, early detection and treatment can slow, or even halt the progression of the disease.

What causes glaucoma?

The eye constantly produces aqueous, the clear fluid that fills the anterior chamber (the space between the cornea and iris). The aqueous filters out of the anterior chamber through a complex drainage system. The delicate balance between the production and drainage of aqueous determines the eye’s intraocular pressure (IOP). Most people’s IOPs fall between 8 and 21. However, some eyes can tolerate higher pressures than others. That’s why it may be normal for one person to have a higher pressure than another.

Common types of glaucoma

Open Angle

Open angle (also called chronic open angle or primary open angle) is the most common type of glaucoma. With this type, even though the anterior structures of the eye appear normal, aqueous fluid builds up within the anterior chamber, causing the IOP to become elevated. Left untreated, this may result in permanent damage of the optic nerve and retina. Eye drops are generally prescribed to lower the eye pressure. In some cases, surgery is performed if the IOP cannot be adequately controlled with medical therapy.

Acute Angle Closure

Only about 10% of the population with glaucoma have this type. Acute angle closure occurs because of an abnormality of the structures in the front of the eye. In most of these cases, the space between the iris and cornea is more narrow than normal, leaving a smaller channel for the aqueous to pass through. If the flow of aqueous becomes completely blocked, the IOP rises sharply, causing a sudden angle closure attack.

While patients with open angle glaucoma don’t typically have symptoms, those with angle closure glaucoma may experience severe eye pain accompanied by nausea, blurred vision, haloes around lights, and a red eye. This problem is an emergency and should be treated by an ophthalmologist immediately. If left untreated, severe and permanent loss of vision will occur in a matter of days.

Secondary Glaucoma

This type occurs as a result of another disease or problem within the eye such as: inflammation, trauma, previous surgery, diabetes, tumor, and certain medications. For this type, both the glaucoma and the underlying problem must be treated.


This is a rare type of glaucoma that is generally seen in infants. In most cases, surgery is required.

Signs and Symptoms

Glaucoma is an insidious disease because it rarely causes symptoms. Detection and prevention are only possible with routine eye examinations. However, certain types, such as angle closure and congenital, do cause symptoms.

Angle Closure (emergency)

  • Sudden decrease of vision
  • Extreme eye pain
  • Headache
  • Nausea and vomiting
  • Glare and light sensitivity


  • Tearing
  • Light sensitivity
  • Enlargement of the cornea

Detection and Diagnosis

glauc discs

The above photos show progressive optic nerve damage (indicated by the cup to disc ratio) caused by glaucoma.

Notice the pale appearance of the nerve with the 0.9 cup as compared to the nerve with the 0.3 cup.

Because glaucoma does not cause symptoms in most cases, those who are 40 or older should have an annual examination including a measurement of the intraocular pressure. Those who are glaucoma suspects may need additional testing.

The glaucoma evaluation has several components. In addition to measuring the intraocular pressure, the eye care practitioner will also evaluate the health of the optic nerve (ophthalmoscopy), test the peripheral vision (visual field test), and examine the structures in the front of the eye with a special lens (gonioscopy) before making a diagnosis.

The eye care practitioner evaluates the optic nerve and grades its health by noting the cup to disc ratio. This is simply a comparison of the cup (the depressed area in the center of the nerve) to the entire diameter of the optic nerve. As glaucoma progresses, the area of cupping, or depression, increases. Therefore, a patient with a higher ratio has more damage.

The progression of glaucoma is monitored with a visual field test. This test maps the peripheral vision, allowing the eye care practitioner to determine the extent of vision loss from glaucoma and a measure of the effectiveness of the treatment. The visual field test is periodically repeated to verify that the intraocular pressure is being adequately controlled.

The structures in the front of the eye are normally difficult to see without the help of a special gonioscopy lens. This special mirrored contact lens allows the eye care practitioner to examine the anterior chamber and the eye’s drainage system.


Most patients with glaucoma require only medication to control the eye pressure. Sometimes, several medications that complement each other are necessary to reduce the pressure adequately.

Surgery is indicated when medical treatment fails to lower the pressure satisfactorily. There are several types of procedures, some involve laser and can be done in the office, others must be performed in the operating theatre. The objective of any glaucoma operation is to allow fluid to drain from the eye more efficiently.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Headaches may occur for any number of reasons including: sinus conditions, hypertension, allergies, tumors, hormonal changes, and most frequently, stress. They are not usually associated with problems related to the eyes.

Migraine headaches

Migraine, a type of headache that is often hereditary, usually first surfaces between the ages of 15 and 30. They are most common among women and are thought to be related to stress and some foods.

Migraine headaches may cause visual symptoms such as light flashes, temporary blind spots, and blurred vision. Migraines are thought to be caused by the dilation and constriction of arteries in the head. These headaches can be extremely painful. The pain is often limited to one side of the head, and may be accompanied by nausea and vomiting.

In many cases, migraines are believed to be brought on by stress. This “Friday night” headache often follows the stress relief of a frenetic week during which the blood vessels in the head relax and constrict. Certain foods and additives such as chocolate, alcohol, dairy, and MSG are also attributed to migraines. However, for many, the cause is variable and extremely difficult to pinpoint.

Signs and Symptoms

Eye-related headaches typically occur after extended periods of reading, watching television, computer work, or other close work that requires intense concentration. This type of headache usually disappears after a period of rest. In some cases, headaches may be caused by eyestrain related to eyeglasses. A tendency for the eyes to cross or drift outward may also bring on headaches.

One eye problem known to cause an intense headache is angle-closure glaucoma. With this type of glaucoma, the headache is only part of the problem. Patients suffering from an angle-closure attack also may experience nausea, intense pain around the eye,blurred vision, and haloes around lights.

Headaches caused by eye disease are unique in their symptoms and types of pain. It is important to make detailed notes of your symptoms, type of pain, lifestyle and what you were doing when the headache began. This information is very helpful to the physician to diagnose the type and cause of the headache you are experiencing.

The symptoms from headaches can be extremely variable and depend on the underlying problem. Because the scope of the various types and causes is so immense, the following headaches are described with the typical symptoms as they relate to the eye.

Headaches related to eye fatigue:

  • Headaches that begin after an extended period of reading, computer use, watching television, or close work
  • Burning eyes
  • Fatigue


  • Throbbing pain
  • Sensitivity to light and sound
  • Nausea and vomiting
  • Visual “aura” including: light flashes, jagged lights, missing areas of vision

Acute angle-closure glaucoma

  • Intense headache that is usually centralized over brow area
  • Nausea and vomiting
  • Glare or haloes around lights

Detection and Diagnosis

Your doctor will routinely obtain a complete history and perform a thorough physical examination to rule out systemic causes of the headache. Your eye care practitioner will verify that no eye-related problems are bringing on the headache.


Stress relief, control of blood pressure, or medication to maintain appropriate hormonal levels may be necessary. New glasses or different work lighting may be prescribed by your eye care practitioner.

If you have persistent headaches, it is important to consult your medical doctor about them for a medical evaluation.

With acknowledgement to St. Lukes Eye Hospital.

Herpes simplex is a very common virus affecting the skin, mucous membranes, nervous system, and the eye. There are two types of herpes simplex. Type I causes cold sores or fever blisters and may involve the eye. Type II is sexually transmitted and rarely causes ocular problems.

Nearly everyone is exposed to the virus during childhood. Herpes simplex is transmitted through bodily fluids, and children are often infected by the saliva of an adult. The initial infection is usually mild, causing only a sore throat or mouth. After exposure, herpes simplex usually lies dormant in the nerves that supply the eye and skin.

Later on, the virus may be reactivated by stress, heat, running a fever, sunlight, hormonal changes, trauma, or certain medications. It is more likely to recur in people who have diseases that suppress their immune system. In some cases, the recurrence is triggered repeatedly and becomes a chronic problem.

When the eye is involved, herpes simplex typically affects the eyelids, conjunctiva, and cornea. Keratitis (swelling caused by the infection), a problem affecting the cornea, is often the first ocular sign of the disease. In some cases, the infection extends to the middle layers of the cornea, increasing the possibility of permanent scarring. Some patients develop uveitis, an inflammatory condition that affects other eye tissues.

Signs and Symptomsherpes dendrite

  • Pain
  • Red eye
  • Tearing
  • Light sensitivity
  • Irritation, scratchiness
  • Decreased vision (dependent on the location and extent of the infection)

Detection and Diagnosis

Herpes simplex is diagnosed with a slit lamp examination. Tinted eye drops that highlight the affected areas of the cornea may be instilled to help the eye care practitioner evaluate the extent of the infection.


Treatment of herpes simplex keratitis depends on the severity. An initial outbreak is typically treated with topical and sometimes oral anti-viral medication. The ophthalmologist may gently scrape the affected area of the cornea to remove the diseased cells. Patients who experience permanent corneal scarring as a result of severe and recurrent infections may require a corneal transplant to restore their vision.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Herpes zoster, commonly known as shingles, is caused by the same virus responsible for chicken pox. After the initial exposure, herpes zoster lies dormant in certain nerve fibres. It may become active as a result of many factors such as: aging, stress, suppression of the immune system, and certain medications.

Because of the layout of the nerves that herpes zoster resides in, it only affects one side of the body or face during an outbreak. It begins as a rash that lead to blisters and sores on the skin. When the nerve branch that supplies the eye is involved, the forehead, nose, and eyelids may also be affected. Sores on the nose are a key signal of possible eye involvement.

Herpes zoster can cause several problems with the eye and surrounding skin that may have long term effects. Inflammation and scarring of the cornea, along with conjunctivitis (inflammation of the conjunctiva) and iritis (inflammation of the iris) are typical problems that require treatment. In some cases, the retina and optic nerve are involved. Eye problems caused by severe or chronic outbreaks of herpes zoster may include: glaucoma, cataract, double vision, and scarring of the cornea and eyelids.

Many who experience this infection find it extremely painful. This acutely painful phase usually lasts several weeks; however, some continue to experience pain or neuralgia long after the outbreak has cleared. This is known as post-herpetic neuralgia.

Signs and Symptoms

Herpes zoster causes a wide range of problems affecting the skin and the eye. They range in severity depending on the extent of the outbreak. Some problems listed occur indirectly from the inflammation caused by the disease.

Problems affecting the body

  • Flu-like symptoms (fever, headache, fatigue)
  • Rash
  • Red, sensitive, sore skin
  • Blisters and sores on the skin
  • Pain (may be burning or throbbing), itching and tingling

Problems affecting the eye

  • Redness
  • Light sensitivity
  • Swollen eyelids
  • Dry eyes
  • Blurred vision (depending on how the eye is affected)
  • Corneal inflammation that may lead to scarring
  • Inflammation inside the eye and optic nerve
  • Glaucoma
  • Cataract
  • Double vision
  • Loss of sensation

Detection and Diagnosis

When the eye is affected, the eye care practitioner will perform a thorough examination with a slit lamp microscope and an ophthalmoscope. Visual acuity and intraocular pressure are also monitored. Signs of breakout on the face and body are noted.


Herpes zoster is treated with anti-viral, pain and anti-inflammatory medications. Eye drops and ointments may be prescribed to treat ocular problems. In some cases, secondary conditions caused by herpes zoster may require surgery.

Those who are infected should avoid contact with people who may be more susceptible to contracting the disease such as: the elderly, children, pregnant women, or anyone with a compromised immune system.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Hyphaema is a term used to describe bleeding in the anterior chamber (the space between the cornea and the iris) of the eye. It occurs when blood vessels in the iris bleed and leak into the clear aqueous fluid. Hyphaemas are usually characterized by pooling of blood in the anterior chamber that may be visible to the naked eye. The red blood cells of very small hyphaemas are visible only with magnification. Even the slightest amount of blood in the anterior chamber will cause decreased vision when mixed in the clear aqueous fluid.

Bleeding in the anterior chamber is most often caused by blunt trauma to the eye. It may also be associated with surgical procedures. Other causes include abnormal vessel growth in the eye and certain ocular tumors.

Signs and Symptoms

  • Decreased vision (depending on the amount of blood in the eye, vision may be reduced to hand movements and light perception only)
  • Pool of blood in the anterior chamber
  • Elevated intraocular pressure (in some cases)

Detection and Diagnosis

It is very important for the eye care practitioner to determine the cause of the hyphaema. If the hyphaema is related to an ocular injury, any detail regarding the nature of the trauma is helpful. The eye care practitioner will assess visual acuity, measure intraocular pressure, and examine the eye with a slit lamp microscope and ophthalmoscope.


The treatment is dependent on the cause and severity of the hyphaema. Frequently, the blood is reabsorbed over a period of days to weeks. During this time, the eye care practitioner will carefully monitor the intraocular pressure for signs of the blood preventing normal flow of the aqueous through the eye’s angle structures. If the eye pressure becomes elevated, eye drops may be prescribed to control it.The pupils are also evaluated to rule out damage to the iris.

In some cases, a procedure is performed to irrigate the blood from the anterior chamber to prevent secondary complications such as glaucoma and blood stains on the cornea.

Patients with significant hyphaemas must rest and avoid strenuous activity to allow the blood to reabsorb.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Iritis is an inflammatory problem of the iris, the coloured part of the eye. It often occurs for unknown reasons, but it may be linked to certain diseases affecting the body, infections, previous eye surgery, or injury.

Iritis may affect one or both eyes. It is sometimes a chronic, recurring condition.

Signs and Symptoms

  • Red eye
  • Light sensitivity
  • Pain that may range from aching or soreness to intense discomfort
  • Small pupil
  • Tearing

Detection and Diagnosis

The eye care practitioner can detect iritis during an examination of the eye with a slit lamp microscope. Among other things, the eye care practitioner will look for microscopic white cells floating inside the eye which are a sign of inflammation. The eye care practitioner will also carefully examine inside the eye to determine if other parts of the eye are involved.


Steroids and anti-inflammatory drops are prescribed to reduce inflammation in the eye. Dilating drops also make the eye more comfortable by relaxing the muscle that constricts the pupil.

Iritis must be treated to avoid permanent problems such as scarring inside the eye.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Keratoconus is a degenerative disease of the cornea that causes it to gradually thin and bulge into a cone-like shape. This shape prevents light from focusing precisely on the macula. As the disease progresses, the cone becomes more pronounced, causing vision to become blurred and distorted. Because of the cornea’s irregular shape, patients with keratoconus are usually very nearsighted and have a high degree of astigmatism that is not correctable with glasses.

Keratoconus is sometimes an inherited problem that usually occurs in both eyes.


Signs and Symptoms

  • Nearsightedness
  • Astigmatism
  • Blurred vision – even when wearing glasses and contact lenses
  • Glare at night
  • Light sensitivity
  • Frequent prescription changes in glasses and contact lenses
  • Eye rubbing

Detection and Diagnosis

Keratoconus is usually diagnosed when patients reach their 20’s. For some, it may advance over several decades, for others, the progression may reach a certain point and stop.

Keratoconus is not usually visible to the naked eye until the later stages of the disease. In severe cases, the cone shape is visible to an observer when the patient looks down while the upper lid is lifted. When looking down, the lower lid is no longer shaped like an arc, but bows outward around the pointed cornea. This is called Munson’s sign.

Special corneal testing called topography provides the eye care practitioner with detail about the cornea’s shape and is used to detect and monitor the progression of the disease. A pachymeter may also be used to measure the thickness of the cornea.


The first line of treatment for patients with keratoconus is to fit rigid gas permeable (RGP) contact lenses. Because this type of contact lens is not flexible, it creates a smooth, evenly shaped surface to see through. However, because of the cornea’s irregular shape, these lenses can be very challenging to fit. This process often requires a great deal of time and patience.

When vision deteriorates to the point that contact lenses no longer provide satisfactory vision, corneal transplant surgery may be necessary to replace the diseased cornea with a healthy one.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Age-related macular degeneration (ARMD) is a degenerative condition of the macula (the central retina). It is one of the most common causes of vision loss in the over 50’s, and its prevalence increases with age. AMD is caused by hardening of the arteries that nourish the retina. This deprives the sensitive retinal tissue of oxygen and nutrients that it needs to function and thrive. As a result, the central vision deteriorates.

macd effects
This example demonstrates what a patient with advanced macular degeneration sees.

Macular degeneration varies widely in severity. In the worst cases, it causes a complete loss of central vision, making reading or driving impossible. For others, it may only cause slight distortion. Fortunately, macular degeneration does not cause total blindness since it does not affect the peripheral vision.

What is the difference between wet and dry macular degeneration?

AMD is classified as either wet or dry. About 10% of patients who suffer from macular degeneration have wet AMD. This type occurs when new vessels form to improve the blood supply to oxygen-deprived retinal tissue. However, the new vessels are very delicate and break easily, causing bleeding and damage to surrounding tissue.

macd wet macd dry

Patients with wet macular degeneration develop new blood vessels under the retina. This causes haemorrhage, swelling, and scar tissue but it can be treated with laser in some cases.

Dry maculardegeneration,
although more common, typically results in a less severe, more gradual loss of vision.

The dry type is much more common and is characterized by drusen and loss of pigment in the retina. Drusen are small, yellowish deposits that form within the layers of the retina.

What causes macular degeneration?

Macular degeneration may be caused by variety of factors. Genetics, age, nutrition, smoking, and sunlight exposure may all play a role.

Signs and Symptoms

  • Loss of central vision. This may be gradual for those with the dry type. Patients with the wet type may experience a sudden decrease of the central vision.
  • Difficulty reading or performing tasks that require the ability to see detail
  • Distorted vision (Straight lines such as a doorway or the edge of a window may appear wavy or bent.)


There is no proven medical therapy for dry macular degeneration. In selected cases of wet macular degeneration, laser photocoagulation is effective for sealing leaking or bleeding vessels. Unfortunately, laser photocoagulation usually does not restore lost vision, but it may prevent further loss. Early diagnosis is critical for successful treatment of wet macular degeneration.Patients can help the eye care practitioner detect early changes by monitoring vision at home with an Amsler grid.

Nutrition and macular degeneration

Several recent studies have indicated a strong link between nutrition and the development of macular degeneration. It has been scientifically demonstrated that people with diets high in fruits and vegetables (especially leafy green vegetables) have a lower incidence of macular degeneration. More studies are needed to determine if nutritional supplements can prevent progression in patients with existing disease.

Tips for AMD patients

If you’ve been diagnosed with AMD, making a few simple lifestyle changes could have a positive impact on the health of your retina.

  • Monitor your vision daily with an Amsler grid. By checking your vision regularly, changes that may require treatment can be detected early.
  • Take a multi-vitamin with zinc. (check with your eye care practitioner for a recommendation). Antioxidants, along with zinc andlutein are essential nutrients, all found in the retina. It is believed that people with AMD may be deficient in these nutrients.
  • Incorporate dark leafy green vegetables into your diet. These include spinach, collard greens, kale and turnip greens.
  • Always protect your eyes with sunglasses that have UV protection. Ultraviolet rays are believed to cause damage to the pigment cells in the retina.
  • Quit smoking. Smoking impairs the body’s circulation, decreasing the efficiency of the retinal blood vessels.
  • Exercise regularly. Cardiovascular exercise improves the body’s overall health and increases the efficiency of the circulatory system.

These are a few tips to make reading easier:

  • Use a halogen light. These have less glare and disperse the light better than standard light bulbs.

  • Shine the light directly on your reading material. This improves the contrast and makes the print easier to see.

  • Use a hand-held magnifier. A magnifier can increase the print size dramatically.

  • Try large-print or audio books. Most libraries and bookstores have special sections reserved for these books.

  • Consult a low vision specialist. These professionals are specially trained to help visually impaired patients improve their quality of life. After a personalized consultation, they can recommend appropriate magnifiers, reading aids, practical tips, and many resources.

Amsler Grid


  • Use a bright reading light
  • Wear your reading glasses if appropriate
  • Hold the chart approximately 14-16 inches from your eye
  • Cover one eye
  • Look at center dot
  • Note irregularities (wavy, size, gray, fuzzy)
  • Repeat the test with your other eye
  • Contact your eye care practitioner if you see any irregularities or notice any changes

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Macular hole is a problem that affects the very central portion of the retina. It happens for a variety of reasons such as: eye injuries, certain diseases, and inflammation inside the eye. However, the most common cause is related to the normal aging process.

The vitreous gel inside the eye is firmly attached to the macula. With age, the vitreous becomes thinner and separates from the retina. Sometimes this creates traction on the macula, causing a hole to form.

Macular holes often begin gradually and affect central vision depending on the severity and extent of the problem. Partial holes only affect part of the macular layers, causing wavy, distorted, blurred vision. Patients with full-thickness macular holes experience a complete loss of central vision.

Signs and Symptoms

The severity of the symptoms is dependent on whether the hole is partial or full-thickness.

  • Blurred central vision
  • Distorted, “wavy” vision
  • Difficulty reading or performing tasks that require seeing detail
  • Gray area in central vision
  • Central blind spot

Detection and Diagnosis

Visual acuity testing, Amsler grid, and ophthalmoscopy are all performed to evaluate the macula’s health and function. The retina specialist may also order photographs of the macula prior to performing surgery to repair the hole.


Some macular holes seal spontaneously and require no treatment. In many cases, surgery is necessary to close the hole and restore useful vision.

Macular holes are repaired with surgery. During the operation, the surgeon first gently removes the vitreous gel with a procedure called vitrectomy. This eliminates any traction on the macula. A gas bubble is injected in the eye to place gentle pressure on the macula and help the hole to seal. In many cases, patients enjoy functional vision after the bubble has dissipated and the eye has healed.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

A naevus is typically a flat, benign, pigmented area that may appear inside the eye or on its surface. Naevae commonly appear on the choroid (the layer just behind the retina), the iris, and the conjunctiva. Naevae are similar to freckles, and don’t typically change or grow.nevusirislesion

Signs and Symptoms

  • Brownish, freckle-like spot
  • Usually flat

Detection and Diagnosis

Naevae of the conjunctiva or iris can be detected with a slit lamp microscope. If the naevus occurs within the eye, it is evaluated with an ophthalmoscope.


Naevae are usually harmless, but it’s always wise to monitor them for changes. This can be done with photos and sometimes ultrasound. The eye care practitioner will document the size, shape and whether the naevus is elevated. In rare cases, the naevus must be biopsied and examined for melanoma (cancer) cells.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

New (neo) blood vessel growth (vascularization) on the cornea. Often caused by contact lens complications. The blood vessels in this photograph (arrows) are abnormal in size, shape, and location, indicating corneal neovascularization.


Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.


Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Ocular rosacea is associated with a chronic skin condition known as acne rosacea. The problem usually affects those with light skin, and is characterized by redness and bumps concentrated on the forehead, nose and cheeks. One of the earliest symptoms of rosacea (often experienced during puberty) is facial flushing brought on by changes in body temperature, emotion, or hot drinks. Eventually, the skin may become chronically red, irritated and inflamed.

Approximately 60% of patients with rosacea develop related problems affecting the eye (ocular rosacea). Patients with ocular rosacea most commonly experience irritation of the lids and eye, occurring when the oil-producing glands of the lids become obstructed. Styes, blepharitis, episcleritis, and chronically red eyes are also typical conditions. Ocular rosacea may also affect the cornea, causing neovascularization (abnormal blood vessel growth), infections, and occasionally ulcers.

Signs and Symptoms

Acne Rosacea

  • Red, flushed skin
  • Breakouts or papules concentrated on the nose, forehead, and cheeks
  • Facial flushing after drinking alcohol, eating hot or spicy foods, or events that increase body temperature
  • Dry, flaking skin

Ocular Rosacea

  • Chronically red eyes and lid margins
  • Irritated eyelids (blepharitis)
  • Styes (chalazion)
  • Dry, irritated eyes
  • Burning
  • Foreign body sensation

Detection and Diagnosis

Those with ocular rosacea are frequently under the care of a dermatologist and are referred for treatment when the patient develops related eye conditions. However, the eye care practitioner may also make the initial diagnosis with a routine eye exam and evaluation of the skin.


Patients with this condition should avoid hot drinks, spicy foods, alcohol, or activities that cause the body temperature to become elevated. Care should be taken to protect the skin from ultraviolet light exposure by using sunscreen with a high SPF factor and wearing hats and sunglasses when outdoors.

Controlling skin inflammation may give marked relief of the eye conditions. Because of this, the eye care practitioner and dermatologist often work together to treat the problem. Eye-related symptoms can often be relieved with warm (not hot) compresses on the lids, eyelid scrubs and artificial tears. Topical and/or oral antibiotics may also be prescribed to reduce symptoms.

With acknowledgement to St. Lukes Eye Hospital.

Optic neuritis refers to swelling or inflammation of the optic nerve. It is often associated with diseases causing demyelination (a loss of the protective myelin layer of the the nerve) of the optic nerve, but sometimes the cause is unknown. Multiple sclerosis (MS) is the disease most often associated with optic neuritis. It is not uncommon to have an episode of optic neuritis prior to being diagnosed with MS. In fact, optic neuritis is often the initial sign of MS.

Most patients with optic neuritis experience a sudden onset of decreased vision along with pain and soreness when moving the eye. Optic neuritis usually affects only one eye and may be a recurring problem with certain diseases such as MS.

Signs and Symptoms

The following symptoms of optic neuritis may not occur in all cases; however, they are the most common problems associated with the condition.

  • Pain with eye movement (more than 90% of patients)
  • Tender, sore eye
  • Mild to severe decrease in central vision
  • Dull, dim vision
  • Reduced color perception
  • Decreased peripheral vision
  • Central blind spot
  • Fever
  • Headache
  • Nausea
  • Decreased vision following exercise, hot bath or shower (activities that elevate body temperature)

Detection and Diagnosis

The eye care practitioner takes several factors into consideration when diagnosing optic neuritis. The problem may not always be readily apparent by examining the optic nerve, so special attention is paid to the patient’s symptoms and other tests. Pain with eye movement is a hallmark symptom of optic neuritis. The eye care practitioner may evaluate the pupils’ reaction to light and order tests such as: visual field, color vision, and imaging of the brain (MRI).


Since the Optic Neuritis Treatment Trial (ONTT), physicians have discovered that treating patients with intravenous steroid medication (but not oral steroids) reduces the risk of developing MS later on. This finding is very significant since approximately 50% of those who experience an initial occurrence of optic neuritis will develop MS. While this treatment has little if any impact on vision, it is important for overall health.

Optic neuritis characteristically improves over a period of days to weeks. For some, a complete recovery may take months.

With acknowledgement to St. Lukes Eye Hospital.

A pinguecula (pin gwe’ cue la) is a benign, yellowish growth that forms on the conjunctiva. They usually grow near the cornea on the nasal side. Pingueculae (plural form of pinguecula) are thought to be caused by ultraviolet light and are most common among people who spend a great deal of time outdoors.

This growth does not affect vision, but may cause irritation if it becomes elevated. In rare cases, the pinguecula may gradually extend over the cornea, forming a pterygium.

Signs and Symptoms

Pingueculae are harmless growths and rarely cause symptoms.

  • Yellowish, raised area on the conjunctiva
  • Irritation and scratchiness
  • Dry eye
  • Occasional inflammation of the conjunctiva
  • Redness if the area becomes irritated

Detection and Diagnosis

Pingueculae can often be seen with the naked eye; however, the eye care practitioner diagnoses the growth with a careful examination with a slit lamp microscope.


Because of their benign nature, pingueculae rarely require treatment. Occasionally, the growth may become inflamed, causing irritation and dryness. The eye care practitioner may prescribe artificial tears for lubrication and mild anti-inflammatory medication to reduce swelling.

With acknowledgement to St. Lukes Eye Hospital.

Pterygium (pronounced ter ig ee um) is a raised, wedge-shaped growth of the conjunctiva. It is most common among those who live in tropical climates or spend a lot of time in the sun. Symptoms may include irritation, redness, and tearing. Pterygia are nourished by tiny capillaries that supply blood to the tissue. For some, the growth remains dormant; however, in other cases it grows over the central cornea and affects the vision. As the pterygium develops, it may alter the shape of the cornea, causing astigmatism. Before the pterygium invades the central cornea, it should be removed surgically.

Since pterygia are most commonly caused by sun exposure, protecting the eyes from sun, dust and wind is recommended. Instilling artificial tears liberally is also helpful to decrease irritation. In some cases, steroid drops are prescribed to reduce inflammation.

With acknowledgement to St. Lukes Eye Hospital.

Ptosis (pronounced toe’ sis), or drooping of the upper eyelid, may occur for several reasons such as: disease, injury, birth defect, previous eye surgery and age. In most cases, it is caused by either a weakness of the levator muscle (muscle that raises the lid), or a problem with the nerve that sends messages to the muscle.

Children born with ptosis may require surgical correction of the lid if it covers the pupil. In some cases, it may be associated with a crossed or misaligned eye (strabismus). Left untreated, ptosis may prevent vision from developing properly, resulting in amblyopia, or lazy eye.

Patients with ptosis often have difficult blinking, which may lead to irritation, infection and eyestrain. If a sudden and obvious lid droop is developed, an eye care practitioner should be consulted immediately.

Signs and Symptoms

The causes of ptosis are quite diverse. The symptoms are dependent on the underlying problem and may include:

  • Drooping lid (may affect one or both eyes)
  • Irritation
  • Difficulty closing the eye completely
  • Eye fatigue from straining to keep eye(s) open
  • Children may tilt head backward in order to lift the lid
  • Crossed or misaligned eye
  • Double vision

Detection and Diagnosis

When examining a patient with a drooping lid, one of the first concerns is to determine the underlying cause. The ophthalmic surgeon will measure the height of the eyelid, strength of the eyelid muscles, and evaluate eye movements and alignment. Children may require additional vision testing for amblyopia.


Ptosis does not usually improve with time, and nearly always requires corrective surgery by an ophthalmologist specializing in plastic and reconstructive surgery. In most cases, surgery is performed to strengthen or tighten the levator muscle and lift the eyelid. If the levator muscle is especially weak, the lid and eyebrow may be lifted. Ptosis surgery can usually be performed with local anaesthesia except with young children.

With acknowledgement to St. Lukes Eye Hospital.

Upon awakening, patients often experience severe pain, blurred vision, and light sensitivity when the eyelid pulls the loosened epithelial cells off the cornea. After the cornea heals, the problem recurs as the name implies unless the condition is treated. Recurrent corneal erosion may affect one or both eyes, depending on the underlying cause.

Signs and Symptoms

  • Severe pain (especially after awakening)
  • Blurred vision
  • Foreign body sensation
  • Dryness and irritation
  • Tearing
  • Red eye
  • Light sensitivity

Detection and Diagnosis

Using a slit lamp microscope, the eye care practitioner examines the corneal layers under high magnification. Eye drops containing green dye called fluorescein are usually instilled to stain the areas of missing epithelium, allowing the eye care practitioner to evaluate the size and depth of the erosion.


Salt solution drops or ointment are usually prescribed as the first line of treatment. This medication helps the epithelium to adhere better to Bowman’s layer of the cornea. Artificial tears are also recommended to keep the cornea moist.

Those with underlying corneal dystrophy may require additional treatment. This usually includes an in-office procedure where the epithelium is either gently removed, or microscopic “spot welds” are made on the cornea to encourage the epithelium to bond securely to Bowman’s layer underneath.

Patients who continue to suffer from recurrent corneal erosions despite the treatments described, may benefit from phototherapeutic keratectomy (PTK). This involves removal of the superficial layer of corneal cells using the Excimer laser to encourage proper healing.

With acknowledgement to St. Lukes Eye Hospital.

Retinal Tear

Retinal tears commonly occur when there is traction on the retina by the vitreous gel inside the eye. In a child’s eye, the vitreous has an egg-white consistency and is firmly attached to certain areas of the retina. Over time, the vitreous gradually becomes thinner, more liquid and separates from the retina. This is known as a posterior vitreous detachment (PVD).

PVDs are typically harmless and cause floaters in the eye; but in some cases, the traction on the retina may create a tear. Retinal tears frequently lead to detachments as fluids seep underneath the retina, causing it to separate and detach.

Retinal Detachmentretinal detachment

A retinal detachment occurs when the retina’s sensory and pigment layers separate. Because it can cause devastating damage to the vision if left untreated, retinal detachment is considered an ocular emergency that requires immediate medical attention and surgery. It is a problem that occurs most frequently in the middle-aged and elderly.

There are three types of retinal detachments. The most common type occurs when there is a break in the sensory layer of the retina, and fluid seeps underneath, causing the layers of the retina to separate. Those who are very nearsighted, have undergone eye surgery, or have experienced a serious eye injury are at greater risk for this type of detachment. Nearsighted people are more susceptible because their eyes are longer than average from front to back, causing the retina to be thinner and more fragile.

The second most common type occurs when strands of vitreous or scar tissue create traction on the retina, pulling it loose. Patients with diabetes are more likely to experience this type.

The third type happens when fluid collects underneath the layers of the retina, causing it to separate from the back wall of the eye. This type usually occurs in conjunction with another disease affecting the eye that causes swelling or bleeding.

Signs and Symptoms

  • Light flashes
  • “Wavy,” or “watery” vision
  • Veil or curtain obstructing vision
  • Shower of floaters that resemble spots, bugs, or spider webs
  • Sudden decrease of vision

Detection and Diagnosis

Retinal detachments are usually found because the patient calls the eye care practitioner’s office with a symptom listed above. It is critical that these problems are reported early, because early treatment can greatly improve the chance of restoring vision.

The eye care practitioner makes the diagnosis of a retinal detachment after thoroughly examining the retina with ophthalmoscopy. The retinal surgeon’s first concern is to determine whether the macula (the center of the retina) is attached. This is critical because the macula is responsible for the central vision. Whether or not the macula is attached determines the type of corrective surgery required and the patient’s chances of having functional vision after the operation.

Ultrasound imaging of the eye is also very useful for the retinal surgeon to see additional detail of the condition of the retina from several angles.


There are a number of ways to treat retinal detachment. The appropriate treatment depends on the type, severity and location of the detachment.

Pneumatic retinopexy is one type of procedure to reattach the retina. After numbing the eye with a local anaesthesia, the surgeon injects a small gas bubble into the vitreous cavity. The bubble presses against the retina, flattening it against the back wall of the eye. Since the gas rises, this treatment is most effective for detachments located in the upper portion of the eye. In order to manipulate the bubble into the ideal location, the surgeon may ask the patient to keep his or her head in a specific position.

The gas bubble slowly absorbs over the next 1-2 weeks. At that time, an additional procedure is usually performed to “tack down” the retina. This can be done either with cryotherapy, a procedure that uses nitrous oxide to freeze the retina, sealing it in place, or with laser. Local anaesthesia is used for both procedures.

Some types of retinal detachments, because of their location or size, are best treated with a procedure called a scleral buckle. With this technique, a tiny sponge or band made of silicone is attached to the outside of the eye, pressing inward and holding the retina in position. After removing the vitreous gel from the eye with a procedure called a vitrectomy, the surgeon usually seals a few areas of the retina into position with laser or cryotherapy. The scleral buckle is not visible and remains permanently attached to the eye. This technique of reattaching the retina may elongate the eye, causing nearsightedness.

In rare cases where other types of retinal detachment surgeries are either inappropriate or unsuccessful, silicone oil may be used to reattach the retina. The vitreous gel is removed and replaced with silicone oil, which presses the retina into place. While the oil is inside the eye, the vision is extremely poor. After the retina has resealed itself against the back of the eye, a second procedure may be performed to remove the oil.

What you can do…

Early detection is the key in successfully treating retinal detachments and tears. Awareness of the quality of your vision in each eye is extremely important, especially if you are in a higher-risk group such as those who are nearsighted or diabetic. Compare the vision of your eyes daily by looking straight ahead and covering one eye and then the other.

Notify your doctor immediately if you notice any of the following:

  • An obstruction of your peripheral vision (veil, shadow, or curtain)
  • Sudden shower of floaters
  • Light flashes

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.


Retinal vein occlusion occurs when the circulation of a retinal vein becomes obstructed by an adjacent blood vessel, causing haemorrhages in the retina. Swelling and ischaemia (lack of oxygen) of the retina as well as glaucoma are fairly common complications.

The visual symptoms can vary in severity from one person to the next, and are dependent on whether the central retinal vein or a branch retinal vein is involved. Patients who experience a branch vein occlusion often notice a gradual improvement in their vision as the haemorrhage resolves. Recovery from a central vein occlusion is much less likely since it affects the macula.

This problem appears equally in males and females and is more common after the age of 60.

norm retina   crvo
Normal Retina.   Retinal Vein Occulsion.

Signs and Symptoms

  • Sudden onset
  • Blurred ormissing area of vision (if a branch vein is involved)
  • Severe loss ofcentral vision (if a central vein is involved)

Detection and Diagnosis

Vein occlusion is diagnosed by examining the retina with an ophthalmoscope. Fluorescein angiography may be performed in some cases to study the circulation of the retina and to determine the extent of macular oedema or swelling.


Following a vein occlusion, the primary concern is to treat the secondary complications.If areas of the retina are oxygen-deprived, LASER may be used to prevent growth of delicate vessels that could break, bleed or cause glaucoma.

The following are common risk factors for vein occlusion:

  • Diabetes
  • Hypertension
  • Cardiovascular disease

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Retinitis pigmentosa (RP) is a rare, hereditary disease that causes the rod photoreceptors in the retina to gradually degenerate. The rods are located in the periphery of the retina and are responsible for peripheral and night vision. Cones, another type of photoreceptor, are densely concentrated in the macula. The cones are responsible for central visual acuity and color vision.

The disease may be X-linked (passed from a mother to her son), autosomal recessive (genes required from both parents) or autosomal dominant (gene required from one parent). Since it is often a sex-linked disease, retinitis pigmentosa affects males more than females.

People with RP usually first notice difficulty seeing in dim lighting and gradually lose peripheral vision. The course of RP varies. For some, the affect on vision may be mild. Others experience a progression of the disease that leads to blindness.

In many cases, RP is diagnosed during childhood when the symptoms begin to become apparent. However, depending on the progression of the disease, it may not be detected until later in life.

Signs and Symptoms

  • Difficulty seeing in dim lighting
  • Tendency to trip easily or bump into objects when in poor lighting
  • Gradual loss of peripheral vision
  • Glare sensitivity
  • Loss of contrast sensitivity
  • Eye fatigue (from straining to see)

Detection and Diagnosis

Retinitis pigmentosa is usually diagnosed before adulthood. It is often discovered when the patient complains of difficultly with night vision. The eye care practitioner diagnoses RP by examining the retina with an ophthalmoscope. The classic sign of RP is clumps of pigment in the peripheral retina called “bone-spicules.” A test called electroretinography (ERG) may also be ordered to study the eye’s response to light stimuli. The test gives the eye care practitioner information about the function of the rods and cones in the retina.


There is currently no standard treatment or therapy for retinitis pigmentosa; however, scientists have isolated several genes responsible for the disease. Once RP is discovered, patients and their families are encouraged to seek genetic counseling.

Current Research

Scientists at Johns Hopkins University are developing a micro-computer chip prosthesis called the Multiple-unit Artificial Retina Chipset (MARC). Once implanted in the retina, the chip transmits images to the brain that are captured from a small camera mounted on the patient’s glasses. The chip is still in development and is not yet available for widespread use.

Scientists continue to search for treatments for RP but have yet to find a cure.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Retinopathy of Prematurity (ROP), also known as retrolental fibroplasia, is a potentially blinding condition affecting the retina of newborns. In the 1950’s it was associated with the use of high amounts of oxygen in neonatal units. Today, modern neonatal care has curbed the incidence, yet because the survival rate of low birth weight infants is much higher, the exposure of surviving babies to required oxygen levels is increasing. The factors that put infants at greatest risk of developing ROP are low birth weight (less than 1.6 kilograms) and premature delivery (26-28 weeks).

In babies born prematurely, the growth and development of normal blood vessels in the retina is halted and abnormal vessels may begin to develop. The problem with abnormal vessel growth, known as neovascularization, is that it does not deliver adequate oxygen supply to the retina. In addition, it may cause many secondary problems.

ROP is classified in 5 stages, depending on the extent of the disease. Progression of the disease to later stages can lead to the formation of scar tissue in the retina and complications such as: retinal detachment, vitreous hemorrhage, strabismus, and amblyopia. Many children with ROP develop nearsightedness.

Signs and Symptoms

Because newborns cannot communicate their symptoms, parents, neonatologists, pediatricians and ophthalmologists are keenly aware of risk factors for ROP.

  • Low birth weight (1.6 kilograms or less)
  • The need for any oxygen within the first week after birth
  • Unstable health immediately after birth

Children with ROP as infants should be watched for the following symptoms that could signal underlying problems that may not surface until later:

  • Holding objects very close
  • Difficulty seeing distant objects
  • Favoring or winking one eye
  • Reluctance to use one eye
  • Poor vision (previously undetected by the physician)
  • Sudden decrease of vision
  • Crossed or turned eye

Detection and Diagnosis

Infants at risk for ROP should have an ophthalmic examination at approximately 4-6 weeks of age. After instilling a series of dilating drops in each eye, the eye care practitioner examines the retina with an ophthalmoscope. The examination is often performed while a parent holds the child.

Regardless of whether treatment is required, children should be re-examined at recommended intervals to determine if the progression of the disease has halted, or whether treatment is required.


Some children who develop only stage 1-2 of the disease improve with no treatment. In other cases, treatment is required if it reaches threshold. This is a term that indicates the presence of stage 3 changes.

To prevent the proliferation of abnormal vascularization, areas of the retina may be frozen with a technique called cryotherapy. Alternatively, laser may be used for the same purpose. Both treatments leave permanent scars in the peripheral retina, but they are often successful in preserving central vision.

With acknowledgement to St. Lukes Eye Hospital.

Subconjunctival haemorrhage occurs when a small blood vessel under the conjunctiva breaks and bleeds. It may occur spontaneously or from coughing, heavy lifting, or vomiting. In some cases, it may develop following eye surgery or trauma. Subconjunctival haemorrhage tends to be more common among those with diabetes and hypertension.

While it may look frightening, a subconjunctival haemorrhage is essentially harmless. The blood becomes trapped underneath the clear conjunctival tissue, much like a bruise. The blood is visible because it shows through the thin, clear conjunctiva. The blood naturally absorbs within one to three weeks and no treatment is required.

subconj hem

Signs and Symptoms

  • Red, bloody patch on the white of the eye
  • Painless
  • No change in vision

Detection and Diagnosis

Most patients notice the subconjunctival haemorrhage when looking in the mirror, or a friend or family member points it out.


Although it may look like an emergency, a subconjunctival haemorrhage does not affect the vision and no treatment is required.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.

Temporal arteritis, also known as giant cell arteritis, is an inflammatory condition affecting the medium-sized blood vessels that supply the head, eyes, and optic nerves. The disease usually affects those over 60 years of age and causes the vessels in the temple and scalp to become swollen and tender. Women are approximately 4 times more likely to suffer from this disease then men.

The major concern with temporal arteritis is vision loss, although if allowed to progress, it may affect arteries in other areas of the body. This condition is potentially vision threatening, however, if treated promptly, permanent vision loss can be prevented. Vision is threatened when the inflamed arteries obstruct blood flow to the eyes and optic nerves. If untreated, permanent vision loss can occur from oxygen deprivation to the retina and optic nerve.

Signs and Symptoms

Patients with temporal arteritis usually notice visual symptoms in one eye at first, but as many as 50% may notice symptoms in the fellow eye within days if the condition is untreated.

  • Headache
  • Tenderness of scalp (combing hair may be painful)
  • Pain in temple area (may be excruciating)
  • Transient blurred vision

  • Loss of appetite
  • Fever
  • Fatigue
  • Depression
  • Drooping lid
  • Double vision
  • Sore neck
  • Jaw soreness, especially when chewing food

Detection and Diagnosis

When temporal arteritis is suspected, the doctor will order blood tests including an erythrocyte (red blood cell) sedimentation rate (ESR) and C-reactive protein test. The ESR test measures the time it takes for the erythrocytes to collect in the bottom of a test tube. The sediment layer of erythrocytes is measured in millimeters and recorded. An abnormally high ESR is indicative of active inflammation.

C-reactive protein is produced in the liver. This protein is released when the body responds to an injury or any other event that signals inflammation. C-reactive protein is measured with a blood test.

A biopsy of the temporal artery is usually recommended. The procedure is performed with local anaesthesia. A small section of the temporal artery is removed and examined under magnification for inflammatory cells. This test allows doctors to definitively diagnose temporal arteritis.


The eye care practitioner often works in conjunction with the patient’s physician to treat this disease. The primary treatment for the disease is oral steroid medication to reduce the inflammatory process. Most patients notice an improvement in their symptoms within several days. In some cases, a long-term maintenance dosage of the steroid is required.

With acknowledgement to St. Lukes Eye Hospital.

Uveitis is a general term that refers to inflammation or swelling of the eye’s structures responsible for its blood supply. These structures are collectively known as the uveal tract, and include the iris, ciliary body, and choroid. Uveitis is classified by the structures it affects, the underlying cause, and whether it is chronic (lasting more than 6 weeks), or acute in nature. There are four main categories of uveitis. Anterior uveitis (also known as iritis) involves the iris and ciliary body and is the most common type; intermediate uveitis affects the ciliary body, vitreous and retina; posterior uveitis involves the retina, choroid and optic nerve; and diffuse uveitis affects structures both in the front and back of the eye.

Common causes of uveitis include infection or underlying disease, but in some cases the cause is unknown. Uveitis usually affects people between 20-50 years of age.

Signs and Symptoms

The symptoms of uveitis depend on whether it is anterior, intermediate, posterior or diffuse.


  • Light sensitivity
  • Blurred vision
  • Redness around the iris
  • Pain that may range from aching or soreness to intense discomfort
  • Small pupil
  • Tearing
  • Elevated intraocular pressure


  • Often affects both eyes
  • Floaters
  • Blurred vision


  • Blurred vision
  • Pain (if the optic nerve is involved)


  • Combination of symptoms from anterior, intermediate, and posterior uveitis

Detection and Diagnosis

Uveitis is diagnosed with a thorough examination of the eye with a slit lamp microscope and ophthalmoscopy. Visual acuity and intraocular pressure are also evaluated. In some cases, blood work and others tests are required to rule out underlying systemic disease or infection.


The appropriate treatment for uveitis is dependent on the severity of the disease and the ocular structures involved. Topical eye drops and/or oral medications are prescribed to reduce inflammation. In some cases, medication is required to lower the intraocular pressure.

After the inflammation has subsided, secondary conditions such as scar tissue, cataracts and glaucoma may require treatment.

With acknowledgement to St. Lukes Eye Hospital.

The vitreous space is located posteriorly between the lens of the eye and the retina. It is filled with a material called vitreous which is similar to clear gel. As we age, the normal jelly-like consistency of the vitreous begins to liquefy. The vitreous may contract and pull away from its natural attachments on the inside surface of the eye. When it pulls free, it is often accompanied by light flashes and the appearance of a new black spot or floater.

This is not dangerous, but it can be accompanied by more serious eye conditions such as retinal tears and vitreous haemorrhage. These occur when the strong attachments of the vitreous to the retina do not separate properly, tearing the retina or retinal blood vessels. This often leads to new floaters and persistent light flashes. It is suggested that anyone with symptoms of a vitreous detachment have an eye examination to make certain that a more serious problem is not present.




Normal floaters are not dangerous and are caused by tiny specks of tissue inside the vitreous. When light hits these pieces of tissue, it creates shadows on the retina that appear to float across your field of vision.

It may appear that these specks are on the front surface of your eye, but they are actually inside. Except in rare circumstances, floaters are no cause for alarm and no treatment is necessary. However, a sudden increase in new floaters may indicate a problem, and an eye examination is recommended if this occurs.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.