Each year, cataracts affect millions of people, including more than half of all Americans aged 60 and older. A cataract is a painless clouding of the eye’s natural lens that is caused by a buildup of protein. A cataract can form in one or both eyes. If left untreated, cataracts worsen over time and interfere with everyday activities such as reading or driving. Night vision is usually most affected. When cataracts are in their early stages, people are helped by brighter lighting. As cataracts get worse, however, most people require surgery.
An intraocular lens, or IOL, is the artificial replacement lens implanted when a patient’s natural lens has been surgically removed during cataract surgery. A wide variety of replacement lenses are available to cataract patients, each offering its own advantages for post-surgery vision. The most effective lens to use depends on the patient’s preferences and particular vision goals. Goals for vision differ according to individual occupations and lifestyles. IOLs often eliminate the need for glasses or contacts after cataract surgery, conveniently providing most patients with clear vision.