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
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 eyes 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
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. Its a safe
procedure with a near 100 per cent success rate. Following surgery, its
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.
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 eyedrops, oral
medications, laser treatment or even surgery may be involved. If untreated,
glaucoma can cause blindness, and there are 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 visionthe leading
cause of blindness worldwide, in fact. Macular degeneration is generally
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 diseases
progression. As usual, early detection is key.
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 bodys 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
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
In recent years, an estimated
four million new cases of presbyopia have been diagnosed. Todays
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 arms 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 persons 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.
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