"We've found there is no safe dose of UV-B exposure when it comes to risk of cataract, which means people of all ages, races and both sexes should protect their eyes from sunlight year-round."
Exposure to sunlight increases risk of getting cataracts, according to a Johns Hopkins study.
"We've found there is no safe dose of exposure to the sun's ultraviolet B rays when it comes the risk of cortical cataract, which means people of all ages, races and both sexes should protect their eyes from sunlight year-round, says Sheila West, Ph.D., professor of ophthalmology at the Johns Hopkins Wilmer Eye Institute.
Cataract, a clouding of the eyes' clear lenses, occurs when proteins in the lens change their structure due to UV-B light exposure and block light coming into the eye. Cortical cataracts affect the front of the lens.
West is senior author of a report on the study, published in the August 26 issue of Journal of the American Medical Association. The study was supported by the National Institute on Aging.
The finding comes several years after the so-called "watermen's study," in which West and her colleagues showed that crab fisherman working on Maryland's Chesapeake Bay had more cortical cataract compared to people with less sunlight exposure. The current finding shows that even the general public -- those who work indoors and only get sunlight during leisure activities in the yard or on vacation -- may be at increased risk for cortical cataract if precautions aren't taken.
The Hopkins study, conducted in Salisbury, Md., determined the amount of UV-B exposure in 2,520 adults, age 64 to 84, of whom 26.4 percent were African Americans. The Hopkins researchers photographed the lenses of all participants and questioned them about their use of glasses, sunglasses and hats during work and leisure activity, as well as the geographic locations of these activities.