Yes. All you need to protect against sun damage is a pair of glasses that offers 99 or 100 percent protection against both UVA (ultraviolet A) and UVB (ultraviolet B) rays. Those labeled “UV 400” are also effective.

“If your sunglasses block 100 percent of UVA and UVB, you don’t have to spend $250 for designer glasses,” said Dr. Kathryn Colby, director of the clinical research center at the Massachusetts Eye and Ear Infirmary.

Epidemiological evidence suggests that decades of exposure to the sun’s rays can lower the age at which people get cataracts, or cloudiness of the lens inside the eye.

Normally, people begin to get cataracts in their 70s and 80s, but fishermen and others who work in the sun may get cataracts in their 50’s and 60s, said Dr. Elliott Myrowitz [cq], assistant professor of ophthalmology at Johns Hopkins. Cataracts are highly treatable with a surgical procedure in which doctors remove the old, cloudy lens and insert an artificial one.

Cancer of the surface of the eye, though rare, may also be linked to sun exposure.

Aside from basic UVA and UVB protection, the only thing to consider when buying sunglasses is that they are physically comfortable enough that you don’t keep taking them off, Myrowitz said, and that they are not so dark that your vision is impaired.