Cataracts are the most common cause of vision loss in people over age 40 and blindness worldwide. A cataract is a clouding of the eye's natural lens, which lies in the middle part of the eye that helps to focus light onto the retina (light-sensitive tissue at the back of the eye). The most common symptoms of a cataract are blurry vision, sensitivity to light and glare, and increasing difficulty with night vision. Symptoms of early cataract may be improved with new glasses, brighter lighting, anti-glare sunglasses, or magnifying lenses. If these measures do not help, surgery is an option that involves removing the cloudy lens and replacing it with an intraocular lens (IOL) implant, thus allowing light to properly enter the eye again.
Risk factors for cataracts include age, diabetes, excessive exposure to ultraviolet radiation, prolonged use of corticosteroid medications, and smoking. Cataracts can affect the center of the lens (nuclear cataracts), the edges of the lens (cortical cataracts), and the back of the lens (posterior subcapsular cataracts). Although most cataracts are related to aging, other types of cataracts include secondary cataracts (from health problems like diabetes or due to steroid use), traumatic cataracts (after an eye injury), and congenital cataracts (present at birth).
Have your eyes examined yearly. Your optometrist will perform a dilated eye exam including a visual acuity test and refraction to assess your risk for a cataract and discuss appropriate treatment options.