A cataract is a painless, cloudy area in the lens of your eye. A cataract blocks light from reaching the retina (the nerve layer at the back of the eye) and may cause vision problems.
Cataracts are common in older adults and are linked to aging. Smoking and exposure to too much sunlight are other risk factors. Cataracts can also happen after an eye injury, as a result of eye disease, after you use certain medicines, or as a result of health problems such as diabetes.