The condition where the lens of the eye becomes cloudy is a cataract.
The eye’s natural lens is normally transparent and helps focus light onto the retina. A cataract develops when proteins and other structures within the lens become damaged or clump together, gradually making the lens less clear. Aging is the most common cause, but cataracts can also follow eye injuries, radiation exposure, diabetes, inherited conditions, or long-term corticosteroid use.
Cataracts often develop slowly and may affect one or both eyes. Typical effects include blurred vision, faded colors, glare, halos around lights, double vision in one eye, and difficulty seeing at night. They are different from glaucoma, which damages the optic nerve, and macular degeneration, which affects the central retina.
An eye examination, often including slit-lamp microscopy, can confirm a cataract. Glasses may help early symptoms, but surgery is the only effective way to remove a visually significant cataract. In modern surgery, the cloudy lens is replaced with an artificial intraocular lens.