Vision Info

Ocular & Visual Conditions

Amblyopia (lazy eye)

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

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

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.

Farsightedness (hyperopia)

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

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

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.

Nearsightedness (myopia)

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

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 (crossed eyes)

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.

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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