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
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
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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