Cataract is any opcity which develops in the crystalline lens of the eye or in its envelope. A cataract occurs when the normally clear lens in your eye becomes cloudy. The clouding impairs vision by preventing the lens from clearly focusing light on the retina at the back of your eye.
Cataract usually develops slowly and causes no pain over time. When significantly less light reaches the retina, your vision becomes impaired.
Possible signs and symptoms
clouded, blurred or dim vision
sensitively to light and glare
the need for brighter light for reading and other activities
frequent changes in eyeglass or contact lens prescription
fading or yellowing of colors
increasing difficulty with vision at night
halos around lights
double vision in a single eye
Possible causes
long term ultraviolet exposure
effects of disease such diabetes
age is usually a result of denaturation of lens proteins
genetic factors - congenital cataracts and may also play a role in predisposing someone to cataracts. Some cataract formation is to be expected in any person over the age of 70. Full half of all people between the ages of 65 and 74 and about 70% of those over 75 have some cataract formation.
cataracts may also be produced by eye injury or physical trauma.
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