Major Causes Of Blindness
Every year 50,000 Americans become blind. Blindness occurs most often with
advancing age, with half of all blind people generally considered to be over
sixty-five. A significant number of blind people, however, are children or
young adults. Here are some of the more common causes.
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CATARACTS -
Opacities and clouding of the eye's lens, known as cataracts, may form and
block the passage of light through the eye. Some people are born with
cataracts, but the incidence increases with age. They are not painful; in
fact the only symptom is blurred, dimmed or double vision. Not all require
surgery, but those large enough to cause serious visual problems require
surgical removal of the lens, implantation of an intraocular lens,
contact lenses,
or corrective glasses.
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DIABETIC RETINOPATHY -
The increased lifespan of diabetics has increased the incidence of this
disorder. Changes in the tiny blood vessels of the diabetic's retina can cause
blindness. Abnormal blood vessels are formed, some may burst and the retina
may even break loose from the back of the eye. Laser treatments to
"seal" blood vessels or reattach the retina may help if undertaken
early. Some diabetics, incidentally, do not experience vision loss.
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GLAUCOMA -
Perhaps one in every seven or eight cases of blindness is due to this
disorder, in which the transparent fluid inside the forward part of the eye
does not drain normally and excess pressure is built up within the eye. If the
pressure is not controlled, the delicate structure of the eye is increasingly
damaged, resulting in blurred vision, a narrowed field of sight and eventually
total blindness. Early symptoms may include blurred vision, halos around lights
and reduced side vision. In the acute type, there is great pain as eye pressure
rises quickly from blocked drainage canals. In the more common chronic type
there is no pain and vision loss is gradual. Many cases are controlled very
well by medication, but surgery is sometimes necessary. Early detection is
important.
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MACULAR DEGENERATION -
As the inner surface or lining at the back of the eye, the retina functions a
little like the film in a camera. The macula is the part of the retina which
forms the center of the "picture" and the sharpest image.
Degeneration or breakdown of the retina may occur, especially with increased
age. The disorder may be slow or rapid, but peripheral vision usually remains
good. Magnifiers may help, and a few people may be helped by laser treatment
to seal off blood vessels which have grown beneath the retina or to repair the
macular's weak spots by removing worn-out tissue and allowing new tissue
growth.
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RETINITIS PIGMENTOSA -
Frequently beginning as what is called "night blindness," this
condition brings degeneration of the retina and the choroid (a related
vascular area), usually involving an abnormal development of excess pigment.
It is hereditary, with a variety of patterns of inheritance and development.
The most common pattern of development is as follows: At approximately age ten
or twelve, the youngster begins to experience some difficulty in seeing at
night and in poorly lighted areas. His visual field also begins to narrow,
frequently resulting in what is commonly termed "tunnel vision"
although he may not realize this at first. The Visual loss is progressive, so
that the individual is usually legally blind by young adulthood and slowly
loses more and more vision thereafter. Many adults with retinitis pigmentosa
have a very tiny field of vision in which they see well under a good light but
which is so small as to be of little use. Total blindness often results. There
is no known treatment.
Many other vision disorders can cause blindness. If you are experiencing
difficulty with your vision, seek attention from a professional
eye specialist immediately. Blindness isn't the end of the world, still
there's no reason to go blind when you don't have to.
