But large segments of the population don't eat many vitamin-rich fruits and vegetables. One recent study, conducted in Phoenix, Ariz., found that 30 percent of a clinic's patients, had below normal levels of vitamin C-a situation that increases susceptibility to a wide range of diseases. The eye's lens helps focus light. Cataracts, caused by free radical damage, clouds the lens, and the result reduces or scatters light entering the eye. Depending on their size and location, cataracts can reduce vision slightly or cause blindness.
Cataracts are the leading cause of blindness worldwide.
Recent studies show that high intake of antioxidant nutrients reduces the likelihood of developing of cataracts. In one study, M. Christina Leske, M.D., of the University Medical Center, Stony Brook, N.Y., found that people taking multivitamins had a 31 percent lower risk of cataracts, and those taking vitamin E supplements had a 57 percent lower risk. In a separate study, Allen Taylor, Ph.D., of the USDA Human Nutrition Research Center on Aging at Tufts University, Boston, tracked 247 women in the ongoing Nurses Health Study. However, high dietary intake vitamin C by itself was not protective, according to Taylor's article in the American Journal of Clinical Nutrition. Several animal experiments point to the value of another antioxidant, alpha-lipoic acid in preventing cataracts.