08/19/1985 at 01:00 AM EDT
They've long been de rigueur for rockers, movie stars and Joe Cools everywhere. Now sunglasses are worn even by the unhip (sales are up 5 to 10 percent and expected to total more than $1 billion this year). This fact of fashion life pleases doctors: Recent research has shown that wearing sunglasses can help prevent serious eye ailments, including cancer of the eyelid, cataracts and retinal damage.
Not that everyone needs sunglasses for healthy eyes. According to Dr. Donald Pitts, 59, a professor of environmental optometry at the University of Houston whose research into the physiology of vision was used by NASA in designing the Apollo astronauts' helmet visors, "People who travel to the office and home again needn't worry about exposure." The eye itself provides natural protection: Both the cornea and the lens block some of the harmful ultraviolet rays. But if you spend hours at a time outdoors—and this includes weekend sun worshipers—then good sunglasses are essential.
Experts say they should cut out more than 75 percent of both ultraviolet and infrared rays, but warn that the only way to be certain that those designer glasses do more than just look good is to ask the optical salesperson or the manufacturer; the tags won't always give you the hard facts you need. Darker isn't necessarily better. Wearing very dark lenses that don't have ultraviolet filtering capabilities can actually be hazardous. "They cause the pupil to dilate," Pitts explains, "allowing the eye to take in more harmful rays than it would if you weren't wearing any sunglasses at all." Another tip: Don't look at the world through glasses that are rose colored—or any other strong tints. They distort color perception, including the red and green tones of traffic lights, which can be particularly dangerous when one drives a car. Dark green is good, but, according to Pitts, gray is best "because it transmits light equally across the spectrum."
So what's it going to cost? Although ultraviolet-filtering prescription glasses can go for $300, there are nonprescription over-the-counter brands for as little as $6. Which proves that glasses that don't strain your eyes don't have to strain your budget either.