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What
is a cataract?
A cataract is a clouding of the normally
clear lens of the eye. It can be compared to
a window that is frosted or
"fogged" with steam. There are
many misconceptions about cataract. It is:
- Not a film over the eye;
- Not caused by overusing the eyes;
- Not a cancer;
- Not spread from one eye to the
other;
- Not a cause of irreversible
blindness.
- Common symptoms of cataract include:
- A painless blurring of vision;
- Glare, or light sensitivity;
- Frequent eyeglass prescription
changes;
- Double vision in one eye;
- Needing brighter light to read;
- Poor night vision;
- Fading or yellowing of colors.
- The amount and pattern of cloudiness
within the lens can vary. If the cloudiness
is not near the center of the lens, you may
not be aware that a cataract is present.
What
causes cataracts?
The most common type of cataract is related
to aging of the eye. Other causes of
cataract include:
- Family history;
- Medical problems, such as diabetes;
- Injury to the eye;
- Medications, such as steroids;
- Long term, unprotected exposure to
sunlight;
- Previous eye surgery.
How
is a cataract detected?
A thorough eye examination by your
ophthalmologist (medical eye doctor) can
detect the presence and extent of a
cataract, as well as any other conditions
that may be causing blurred vision or
discomfort. There may be other reasons for
visual loss in addition to the cataract,
particularly problems involving the retina
or optic nerve. If these problems are
present, perfect vision may not return after
a cataract removal. If such conditions are
severe, removal of the cataract may not
result in any improvement in vision. Your
ophthalmologist can tell you how much visual
improvement is likely.
How
fast does a cataract develop?
How quickly the cataract develops varies
among individuals, and may even vary between
the two eyes. Most cataracts associated with
aging progress gradually over a period of
years. Other cataracts, especially in
younger people and people with diabetes, may
progress rapidly over a few months and cause
vision to worsen. It is not possible to
predict exactly how fast cataracts will
develop in any given person.
How
are cataracts treated?
Surgery is the only way your ophthalmologist
can remove the cataract. However, if
symptoms are mild, a change of glasses may
be all that is needed for you to function
more comfortably. There are no medications,
dietary supplements, exercises or optical
devices that have been shown to prevent or
cure cataracts. Protection from excessive
sunlight may help prevent or slow the
progression of cataracts. Sunglasses that
screen out ultraviolet (UV) light rays or
regular eyeglasses with a clear, anti-UV
coating offer this protection.
When
should surgery be done?
Cataract surgery should be considered when
cataracts cause enough loss of vision to
interfere with daily activities. It is not
true that cataracts need to be
"ripe" before they can be removed.
Cataract surgery can be performed when your
visual needs require it. You must decide if
you can see to do your job and drive safely,
if you can read and watch TV in comfort. Can
you perform daily tasks, such as cooking,
shopping, yard work or taking medications
without difficulty?
What
can I expect from cataract surgery?
Over 1.4 million people have cataract
surgery each year in the United States, 95%
without complications. During cataract
surgery, which is usually performed under
local anesthesia as an outpatient procedure,
the cloudy lens is removed from the eye. In
most cases, the focusing power of the
natural lens is restored by replacing it
with a permanent intraocular lens implant.
Your ophthalmologist performs this delicate
surgery using a microscope, miniature
instruments and other modern technology.
Although it is a common misconception,
lasers are not used to remove cataracts. In
approximately one-fifth of people having
cataract surgery, the natural capsule that
supports the intraocular lens will become
cloudy. Laser surgery is used to open this
cloudy capsule, restoring the clear vision.
After cataract surgery, you may return
almost immediately to all but the most
strenuous activities. You will have to take
eyedrops as your ophthalmologist directs.
Several postoperative visits are needed to
check on the progress of the eye as it
heals. Cataract surgery is a highly
successful procedure. Improved vision is the
result in over 90% of cases, unless there is
a problem with the cornea, retina or optic
nerve. It is important to understand that
complications can occur during or after the
surgery, some severe enough to limit vision.
As with any surgery, a good result cannot be
guaranteed.
Conclusion
Cataracts are a common cause of poor vision,
particularly for the elderly, but they are
treatable. Your ophthalmologist can tell you
whether cataract or some other problem is
the cause for vision loss or discomfort, and
help you decide if cataract surgery is
appropriate for you.
American
Academy of Ophthalmology
P. O. Box 7424 San Francisco, CA 94120-7424
http://www.eyenet.org
Copyright 1984 American Academy of
Ophthalmology
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