A cataract is a clouding of the eye's normally clear lens, leading to a progressive blurring or dimming of vision. It is the world’s leading cause of blindness and among the most common conditions related to aging – by age 65, you have a 50 percent chance of developing a cataract and by age 75, it jumps to 70 percent.

Cataracts can also result from injury, chronic eye diseases, diabetes, or past use of corticosteroid medications or radiation treatments. Some researchers believe that lifestyle habits such as smoking and not wearing sunglasses to protect eyes against ultraviolet light are also risk factors.

A cataract occurs when proteins in the lens begin to clump together, forming a cloudy area. As the cataract progresses, it interferes with vision by distorting or blocking the passage of light. Many cataracts begin to form in your 40s or 50s, but don’t affect vision until years later. Cataracts can even occur in infants, usually the result of an infection during pregnancy.

Initially, a cataract may have little or no effect on vision. As the cataract grows and clouds more of the lens it creates difficulty with reading, driving, and other activities. Other symptoms include:

In the early stages until the cataract worsens, your doctor may simply recommend changing the prescription of your glasses to maximize your vision. When cataracts disrupt your daily life, it may be time for cataract-removal surgery, one of the most frequent procedures done in the U.S..

More than 1.5 million Americans undergo surgery each year to remove the clouded lens, which is usually replaced with a clear, plastic intraocular lens (IOL). This procedure restores normal vision in most cases. You cannot see or feel the lens and it needs no special care. In most cases, you will still need glasses at least for reading after cataract surgery, however newer “accommodating” IOLs can often eliminate the need for reading glasses altogether.