According to WHO: Cataract is clouding of the lens of the eye which impedes the passage of light. Although most cases of cataract are related to the ageing process, cataract may develop after eye injuries, inflammation, and some other eye diseases.”
Globally, cataract (pacification of the lens) is the single most important cause of blindness, and cataract surgery has been shown to be one of the most cost effective health-care intervention. Most Cataract is related to ageing and cannot be prevented, but cataract surgery and insertion of an Intra-Ocular Lens are highly effective, resulting in almost immediate visual rehabilitation. Cataracts are painless. Often people with cataract begin to complain about glare. "When these people have bright lights shined on them, their vision may drop rather dramatically." Colors may seem faded, and eye-glasses or contact lenses may need frequent changing. People with cataract may need increased light to read. If the cataract worsens, lenses may need frequent changing. People with cataract may need to remove the cloudy lens and replace it with a new lens.
Besides age, other factors that scientists believe may put individuals at greater risk for developing a cataract include heredity, alcohol use, smoking, long-term exposure to high levels of the sun's ultraviolet rays, some medications and systemic disorders such as diabetes.
The lens of eye is an important part of seeing clearly. It focuses light onto the retina. In cataract surgery, the affected lens is removed and, replaced.
World : [WHO - 2010]