All content is provided for education and information and is no substitute for the advice of your Optometrist. This information is provided courtesy of the British Columbia Association of Optometrists (B.C.A.O.). The B.C.A.O. assumes no responsibility or liability arising from any errors or omissions or from the use of any information contained herein.
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Glossary
Click on any of the conditions to see full description.
Amblyopia or “lazy eye” describes weak vision or vision loss in one eye that cannot be fully corrected with lenses.
It usually develops in children before age eight. This is also the key time to treat Amblyopia, since results are better the earlier they are implemented. It becomes extremely difficult to treat Amblyopia after age eight. Untreated, Amblyopia can lead to total blindness in the affected eye.
Amblyopia is more than simply an eye health problem. It involves the “wiring” of the nerve impulses from the eyes to the brain. Treatment typically includes vision therapy, eyeglasses and contact lenses or a patch. Surgery alone cannot treat Amblyopia.
Cataracts are a clouding of the eye’s crystalline lens that usually develops slowly over time. (In the case of post-traumatic cataracts however, they can also occur very quickly.) It is the leading cause of poor vision in adults.
Symptoms: Dimmed or blurred vision, double vision, halos or glare around lights, colours appearing less brilliant, feeling of a film over the eyes, frequently cleaning eyes, difficulty driving or reading, and frequently changing or cleaning glasses.
Treatment: If a cataract grows larger or denser, it can be surgically removed. It’s a safe procedure with a near 100 per cent success rate. Following surgery it’s normal to require a change in spectacle correction.
Prevention: Wearing UV protection when outdoors is very helpful. There is also some evidence to suggest that a diet high in beta carotene (vitamin A), selenium and vitamins C and E have preventative benefits. Avoiding cigarette smoke, air pollution and alcohol consumption may also help.
Symptoms such as eyestrain, eye fatigue, dry eyes and headaches are some of the symptoms associated with Computer Vision Syndrome (CVS). Some may experience neck and back aches as well. Millions of computer users suffer from CVS because it is the number one office-related health complaint. All computer users should have a computer eye exam to determine if prolonged computer use puts excess strain on their eyes and be tested to see if they would benefit from computer glasses.
Proper lighting is important since excessive light from windows or too many bright lights inside can increase eyestrain. This can be reduced by use of drapes on windows and by using fewer light bulbs or lower intensity light bulbs. Glare coming from the computer monitor and walls and finished surfaces contribute to eyestrain as well. Using an anti-glare screen on your monitor, decreasing the brightness on your computer screen, painting walls a dark matte finish and applying anti-reflection coating to your glasses can be very helpful. The use of artificial tears may be helpful for dry eyes and irritation associated with CVS.
Did you know computer use can reduce our blinking rate up to 5 times compared to when we are not using a computer? It is also advised that we take 10 minute breaks every hour and keep our focusing system flexible by focusing on a distant object for 10-15 seconds every 30 minutes.
Your workstation should be set up as follows: Your monitor should be 20-28 inches from your eyes; the top of your monitor should be horizontally in line with your eyes (thus your eyes are looking 10-20 degrees downward from the straight ahead position) and your reference material should be on a copy stand or document holder next to your screen illuminated by a desk lamp. Seeing your eye care professional can greatly reduce your CVS symptoms and make computer use a much more comfortable and enjoyable experience.
Diabetic Retinopathy refers to the changes in the retina that occurs over a period of time in diabetes. Your retina is the back part of your eye made up of light sensitive cells. It is fed by blood vessels and when the blood vessels change it can start to cause vision problems.
The blood vessels become fragile and start to break and once the blood leaks out it can affect the vision by creating areas of blurring or floating spots in the eye. These spots may disappear with time. Later the blood vessels may stop carrying blood permanently and the cells will start to die. This loss in sight is gradual but permanent. As the old blood cells die, abnormal cells will grow taking their place. These cells are unable to nourish the retina properly and may grow into the transparent inner part of the eye and further deteriorate vision.
Hyperopia, or farsightedness, is a common refractive error. Approximately 25 per cent of the general population may be affected. Farsighted individuals see better in the distance than up close because the eye does not effectively focus light. Farsightedness is very common among elementary school-age children and a frequent cause of reading and learning difficulties.
Refractive errors such as hyperopia are commonly corrected by eyeglasses or contact lenses. Refractive surgery is another possibility.
Have you ever noticed stinging or burning eyes, scratchiness, stringy mucus around the eyes, irritation from smoke or wind, excess tearing or difficulty wearing contact lenses? These are all symptoms of dry eyes.
Dry eyes are the result of tear evaporation rising as the ability of your tears to stick to the surface of the eye decreases. This happens more as we age, when we stare at a computer screen, work in an area with dry heat or air conditioning or take certain medications that reduce tear production. In simple terms dry eyes are the result of not being able to produce enough tears to keep your eyes comfortable. Everyone needs a film of tears to spread over the eye by blinking for good vision to be possible.
Dry eye can vary in severity but can usually be treated by replenishing tear film using either over the counter eye drops or prescription drops that can actually encourage your eyes to produce more tear film. Other treatments include retaining tears by placing tiny silicone plugs in the eye or sometimes treating an underlying problem such as an infection of the eye lid glands.
Glaucoma is a condition in which elevated pressure in the eye damages the optic nerve. The increased pressure, called intraocular pressure can damage the optic nerve which transmits images to the brain. If damage to the optic nerve from high eye pressure continues, Glaucoma will cause permanent loss of vision. Without treatment Glaucoma can cause total permanent blindness within a few years.
Symptoms: There may be no early warning signs so an optometric exam is crucial. Otherwise pain, blurred vision and the appearance of coloured rings around lights are leading indicators.
Treatment: Once diagnosed, Glaucoma treatments are highly effective. Prescription eye drops, oral medications, laser treatment or even surgery may be involved. If untreated, Glaucoma can cause blindness which has no cures.
Prevention: There may be few symptoms and vision lost to Glaucoma cannot be restored (the condition can only be halted) so frequent monitoring for Glaucoma is essential. The risk for Glaucoma increases dramatically after age 35 and is often hereditary.
Macular degeneration is a condition in which the macula (the part of the retina responsible for sharp reading vision) fails to function efficiently. It is a common cause of impaired reading or detailed vision—the leading cause of blindness worldwide, in fact. Macular degeneration is generally age-related.
Symptoms: Initial signs include blurred reading vision, a weakening of colour vision, distortion or loss of central vision (e.g., a dark spot in the middle of your field of vision) and distortion in vertical lines.
Treatment: Although there is no cure, laser treatment can be effective in slowing the disease’s progression. As usual, early detection is key.
Prevention: Lifelong UV protection is very important. General nutrition is also believed to play a significant preventative role. Zinc may be especially helpful in this regard particularly for zinc-deficient people like seniors. There is also some evidence to suggest that a diet high in beta carotene (vitamin A) and vitamins C and E can protect the macula. However an over-abundance of any vitamin may affect your body’s ability to absorb important nutrients. This is a matter of some debate among health care professionals.
Myopia, more popularly known as nearsightedness, is a common refractive error. Approximately a quarter of the general population may be affected. Myopic individuals see better up close than in the distance. This is because the eye improperly focuses too much light causing blurred vision in the distance.
Refractive errors are commonly corrected by eyeglasses or contact lenses. Refractive surgery and Ortho-Keratology are two other possibilities.
Presbyopia is an inevitable condition in which the ability to focus on close objects decreases over time. Since it is a natural effect of aging it is extremely commonplace.
In recent years an estimated four million new cases of Presbyopia have been diagnosed. Today’s “baby boomer” generation is the most rapidly growing population segment requiring vision correction.
Symptoms: Headaches, blurred near-distance vision, tearing, stinging or a need for more light. People with presbyopia often hold reading material at arm’s length.
Treatment: Reading glasses (typically bifocals) or special contact lenses are useful treatments although the period of adjustment can vary widely. All told there is a wide range of corrective options to review with your Optometrist.
Prevention: There is no recognized prevention available, although focusing difficulties can be relieved with corrective lenses.
Further questions: For such a common condition there are many misconceptions about Presbyopia. For example, it does not affect a person’s lifestyle but Presbyopia can require frequent prescription changes after age 40.
Strabismus or “crossed eyes” is a misalignment of the eyes. One or both eyes may turn in (esotropia), out (exotropia), up (hypertropia) or down (hypotropia). Treatment may include the use of eyeglasses, contact lenses, prisms and/or vision therapy. In extreme cases surgery may be needed.