Cheap Sunglasses and the Naked Eye
-- By Chris Ott
© 2000, RPK&A, Inc.
I never knowingly bought a decent pair of sunglasses. I'd lose or break one pair, and the next would come from some guy selling them on the street. If you get what you pay for, I wasn't getting much.
The problem was, I always felt vaguely nervous about it. Ultraviolet radiation is bad bad bad, the ozone layer is thinning faster than voter participation, and, to make matters worse, I'd heard that it can be more harmful to wear bad sunglasses than no sunglasses at all. Your pupils supposedly widen behind dark glasses, and let in more retina-toasting UV light.
turns out not to be quite so complicated. The cheapest pair of sunglasses--and even clear glass or plastic, for that matter--can block a significant amount of UV radiation. "You're just not going to get in trouble if you block out sunlight," says Dr. Kent Daum, an associate professor in the School of Optometry at the University of Alabama at Birmingham. Daum added that it's also unclear whether a thinning ozone layer is making life any more harmful to the naked eye.
That is, any more harmful than it already is. Ozone hole or no, Daum said there's a clear link between UV radiation and various eye problems. UV radiation can cause trouble including cataracts (a gradual but increasingly severe clouding of the lenses in your eyes), growths on the surface of the eye, and cancer of the eyelids. There's also the possibility of retinal damage, and a temporary but painful sunburn of the eye's surface from high UV exposure over a short time.
Naturally, the damage caused by UV radiation is most intense in bright, direct sunlight, especially at high altitudes, lower latitudes, and at places like the beach or ski slopes where reflected light hits your eyes with a double UV whammy.
For protection, the cheapo brands of sunglasses are better than nothing, and other simple, inexpensive methods offer protection too. According to the American Optometric Association, a simple brimmed hat or cap can cut the amount of UV radiation entering your eyes by about half.
For the best possible eyewear protection, look for lenses that block 99 to 100 percent of both UV-A radiation, which penetrates deeper into the eye, and UV-B radiation, which tends to damage the cornea and lens. Glasses that wrap around the contour of your head are also helpful at blocking out light from the sides.
There are no uniform standards for UV protection, but the A.O.A. puts a seal of acceptance on some glasses, and Daum says you probably can't go wrong by getting sunglasses from an eye-care practitioner. You can also get UV-protection options in prescription eyeglasses and contact lenses.
You can get away with a cheap pair of sunglasses for UV protection, but there's one area where you're more likely to get what you pay for: lens quality. "If you see a pair of sunglasses that are five dollars, I hate to say it, but they're probably just not very good lenses," said Daum. Imperfect lenses can strain your eyes and become uncomfortable to wear, and can also hurt performance in sports or activities that require sharp vision. "There's a connection between how comfortable you are and how well you can do things. If you're out there with just marginal eyewear, you're probably not going to do as well as if you had high-quality visionwear." In particular, Daum recommends polarized lenses for their quality and ability to cut out glare.
A final consideration is lens color. For general use, gray can be a good choice because it reduces light across the spectrum and doesn't distort colors. Reds are still reds, and yellows are still yellows.
Damage to your eyes from ultraviolet light is cumulative and may take a few decades to show up, but Daum says it's increasingly clear that the damage is for real. For the eyes, "there's nothing good that UV radiation is going to do for you."
There may not be much that can be done about damage from UV radiation after it's happened, but at least the methods for avoiding it are pretty simple--especially given what's at stake.