Cataracts, a clouding of the eye’s lens that blurs vision, are a particular problem for adults age 60 and older. Women are at a higher risk than men for developing them, and diabetics are at a very high risk for the condition. Eye experts say long-term exposure to UV radiation can accelerate the development of cataracts.
Proper sunglasses act as sunscreen for the eyes, blocking the same harmful rays that cause sunburn or skin cancer.
"Almost all of the UV light that enters the eye from sunlight is absorbed by the cornea and lens of the eye," says Lee Duffner, M.D., of the Bascom Palmer Eye Institute at the University of Miami.
In addition to cataracts, says Duffner, UV radiation can irritate or even burn the cornea. It also has been linked to skin cancer around the eyelids, and pterygium, an abnormal tissue growth on the white of the eye that can require surgery. Some studies have found that prolonged exposure to sunlight also can increase the risk of macular degeneration, a devastating disease that destroys a portion of the retina.
For all those reasons, wearing sunglasses when you go outside is important protection for your vision, warns Duffner, who has been in practice for 41 years. "And don’t go by price," he adds. "Some inexpensive glasses can be 100 percent UV absorbent and plastic can work just as well as glass."
The important thing is to look for a sticker or tag on the glasses with the UV rating and make sure it says the lenses block 99 to 100 percent of UV-A and UV-B rays, both of which are harmful. Some of the more expensive, brand-name sunglasses also protect against UV-C rays, a less common ultraviolet source, which are mainly blocked by the atmosphere’s ozone layer.