What are cataracts?
The eye's lens is a transparent structure that focuses images on the light-sensitive retina. Cataracts are cloudy areas in the lens. They occur when certain proteins in the lens form abnormal clumps. These clumps gradually get larger and interfere with vision. They distort or block the passage of light through the lens. "Cataract" means "huge waterfall" or "enormous downpour," which is how some people describe their clouded sight, like trying to look through a waterfall.
Cataracts are the world's leading cause of blindness, accounting for about 40% of all cases of blindness. In the United States, most cataracts are age-related and affect more than half of all Americans older than 65 to some degree. Risk factors for developing cataracts at an earlier than expected age include prolonged exposure to bright sunlight and smoking. In many cases, cataracts are age-related. They first appear in the 40s or 50s, but may not affect vision until after age 60. In other cases, cataracts may be caused by eye trauma, long-term diabetes, corticosteroid medications, or radiation treatments.
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