Canadian Association of Optometry – www.opto.ca
Ontario Association of Optometry– optom.on.ca
Ocular & Visual Conditions
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.
Astigmatism is an irregular curvature of the front surface of the eye that results in blurred vision at all distances.
It is a common refractive error, just like nearsightedness and farsightedness. It is usually a condition from birth that progresses over time. Eyeglasses, contact lenses and refractive surgery are all effective treatments for astigmatism.
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.
Diabetic retinopathy, as the name suggests, is associated with diabetes . It is best described as damage to the retina that occurs because of defects in or leakage from the fine blood vessels. The vast majority of those with early diabetic retinopathy are unaware of it. In advanced cases, it can result in vision blurriness and distortion.
Diabetics should ensure they see their Optometrist regularly, scheduling annual eye exams. Since it is a progressive disease, with no treatment, it can cause blindness over time. Your Optometrist can provide the invaluable advice and treatment diabetics require.
Dry eyes are a problem that arises from inadequate or poor lubrication and moisture in one or both eyes. Unable to produce enough tears, afflicted eyes suffer irritation, burning and general discomfort.
Dry eyes may be caused by a number of factors: the natural effects of aging, side effects from medication, or significant time spent in a dry climate. Although there is no cure as such, your Optometrist is able to offer effective treatment to manage dry eyes. Artificial lubricating eye drops enhance tear production, and moist compresses as well as lid massages can help treat dry eyes.
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.
Glaucoma is a condition in which elevated pressure in the eye, damages the optic nerve, causing peripheral and then total blindness. It is widely noted as the second-leading cause of blindness in the U.S.
Symptoms: There may be no early warning signs, so optometrical exams are 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: Because there may be few symptoms, and vision lost to glaucoma cannot be restored (the condition can only be halted), 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.
Retinal detachment is the separation of the retina from the pigment epithelium. It is often caused by holes or tears in the retina, by a tumor, or by fluid pressure in the area.
Retinal detachment occurs among the elderly or, sometimes, following head or eye injuries. There is also a higher rate of incidence among the extremely myopic. B.C. MSP coverage for such patients allows for more frequent eye exams.
In some cases it can be surgically treated. Apart from a sudden loss of vision, other (early) symptoms may include light flashes or an unusual number of “spots and floaters.”
Retinitis pigmentosa is a group of inherited diseases developing inside the pigmented area of the retina of the eye. They tend to become apparent between age 10 and 30, although some types of retinitis pigmentosa occur in childhood or later in life. Vision changes include night blindness, loss of side vision, and “tunnel vision.”
The most common symptom of retinitis pigmentosa is a personal history of visual problems at dusk or in low light. This problem cannot be helped by corrective lenses, however, because the retina itself is deteriorating. Your optometrist can help you adapt to living with retinitis pigmentosa.
Spots and floaters are tiny flecks or threads, which seem to float in front of your eyes. They are experienced by most people. They are often caused by particles of protein trapped in the fluid inside the eye, or by the deterioration of the fluid due to advancing age.
Occasionally they are the result of certain eye diseases or injuries, or they may signal the development of more serious conditions such as retinal detachment. They are usually harmless, but those experiencing a sudden change or increase in “spots and floaters” or flashes of light should consult their eye doctor.
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.
A stye is a visible infection that appears at the edges of an eyelid. Its appearance can vary somewhat, but it is harmless to your vision. Symptoms include a noticeable swelling, some discomfort and tenderness in the affected area.
Most styes heal without treatment, although the application of a hot compress can help. Unlike a pimple, however, styes cannot be manually ruptured and drained. Antibiotic ointments are available for recurring cases.
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.). We assume no responsibility or liability arising from any errors or omissions or from the use of any information contained herein.