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REASONS FOR VISION IMPAIRMENT: CATARACTS
For 2,500 years glaucoma and cataracts were confused until a French ophthalmologist, in 1709, finally differentiated the two conditions. Cataracts are the chief single cause of blindness in the United States, and about three million Americans suffer with them. Of everyone residing in industrialized Western countries who reach age sixty, almost 60 percent of them have some cataract formation. And 100 percent of those reaching age eighty become victimized to some extent by the eye problem.
Cataracts are degenerative conditions of the eyes resulting in cloudiness or opacity in one\'s aging crystalline lenses. They interfere with vision. The opacities may be tiny, which cause little difficulty, to large, dense areas of cloudiness which shut out much of the light that should be entering the eyeball. The retina gets insufficient light to record an image for the brain to readily recognize.
As the lens becomes progressively cloudy, vision becomes dim and blurry. The victim requires a brighter light for reading, or he may need to bring objects quite close to the eye in order to see them. Double vision may occur, as in the perception of a street light from a distance. Stationary spots tend to appear in front of the eyes--appearing as dust spots on eyeglasses when actually they are opaque spots on the human lens. And vision could be more accurate for the cataract patient when he performs an activity in twilight. Eventually the cataract becomes rather obvious to an outside observer by the milky, grayish-white appearance of the person\'s pupil.
It takes approximately two years for a cataract to develop to the point where it totally obstructs the lens. The most common cause is simply increasing age-senile cataract-which occurs from the lens adding new cell layers to the outside periphery similar to the growth of rings of a tree. Such additions make changes in lens resiliency and clarity. The lens tends to get more rigid and less transparent with time. All of us are subject to such lens rigidity and loss of focus, which is known as presbyopia. The decreased transparency taking place later in life is the cataract.
Other less common types - secondary cataracts - are not related to aging. Congenital cataract, present at birth, is a metabolic disease. Galactose cataract, another metabolic condition, comes from milk sugar accumulation. It results from the patient\'s lack of a body enzyme to break down this sugar during metabolism. Such a deficiency leads to absorption of water into the lens and a blocking out of the light. An injury to the eye or lack of suitable
protection against occupational hazards, such as excessive heat or radiation exposure, may also result in cataract formation. Cataract development may be hastened by diabetes, by various nutritional deficiencies, and as a negative side effect of medication used for the treatment of another disease. All of these types are secondary cataracts.
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GENERAL HEALTH
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