Sunshades Keep Your Iris Eyes Smiling

Ho-hum. Another sunny day in Orange County. While folks in other parts of the country are bundling up to protect themselves against the elements, we’re still smearing on the sunscreen.

But no matter how carefully you coat yourself with SPF 15, if your eyes are uncovered, you may be exposing yourself to some serious problems in years to come.

Of course, sunglasses have long been part of the Southern California image, and there are some good medical reasons behind that, say local eye-care professionals. Those warm rays we love so much have been linked, circumstantially, at least, to cataracts and other eye problems.

The worst offender is a form of sunlight we can’t even see: ultraviolet radiation. With a wavelength a little shorter than visible light but somewhat longer than X-rays, ultraviolet light is also what makes skin tan--or burn.

“Any time you’re outside, especially in Southern California, you’re being bombarded with ultraviolet rays,” says Dr. Marilyn Gilbreath, an optometrist and assistant professor at the Southern California College of Optometry in Fullerton. “Even when it’s overcast, the UV rays are still there. So it’s important to wear sunglasses as much as you can, when practical.”

We’re particularly vulnerable in Southern California because of our latitude, Gilbreath says. “We’re a lot closer to the sun than people in Minnesota or Wisconsin. We also have a tendency to be out in it more often.”

Many of our favorite recreational spots also contribute to the problem, says Dr. Clifford Terry, a Fullerton ophthalmologist. At the beach or out sailing on the ocean, skiing in the mountains or exploring the desert, we’re exposed to a greater-than-usual degree of glare. In the mountains, the problem is compounded by the high altitude, which means further exposure to ultraviolet light, Terry says.

Although more studies need to be done, researchers have linked ultraviolet light to several different eye problems, according to Dr. Charles Bittel, a Yorba Linda optometrist.

“On the surface, it can cause a thickening of tissue called a pingueculum, in which the body develops a fatty pad in response to irritation,” Bittel says. That’s pretty much benign, just some little yellowish bumps on the white part of the eye. But in some cases, if there is further irritation, something called a pterygium can develop. Those are growths of the white tissue toward the center of the eye, the cornea, which can cause vision impairment.

“Internally, it’s now pretty much conclusively thought that ultraviolet radiation causes discoloration of the lens--that, of course, is a cataract,” Bittel says. “There’s a correlation between time spent in the sun and the propensity for cataracts. And it’s a cumulative effect.

“There’s also some evidence that the back of the eye, the retina, is possibly altered by ultraviolet light,” Bittel says. Less seriously, exposure to sun sans shades can contribute to wrinkles around the eyes, Terry says, partly because the UV rays contribute to deterioration of the skin, and partly because we naturally squint in response to glare.

But just any sunglasses won’t do, say the eye specialists. And the trendiest, most expensive lenses don’t necessarily offer any better protection than glasses at the lower end of the price spectrum.

“You should look for a pair of sunglasses listed as having a UV coating,” Gilbreath says. Like the light it filters, a UV coating is invisible, and can even be added to the glasses you already have, she says. If you already wear glasses and are bothered by the glare from the sun, Terry says, you need either prescription sunglasses or flip-up lenses. But if you take the flip-up approach, be careful. “Make sure they fit right, that they don’t rub on the lenses,” Terry says. “I’ve seen people scratch up a $250 pair of glasses with those things.”

Polarized lenses can help cut down on glare, Terry says. “Especially coming off the water, or anywhere you have a strong reflection.” A polarized filter, he says, works like a Venetian blind; the only light rays that pass through are those parallel to the filter’s invisible grid.

There is no scientific research on how dark sunglasses should be, Terry says. “The best answer to that is that you really have to test drive them by looking out a very bright window. When you put them on in the store, you can’t tell how they’re going to work outside. For glare purposes, they should be as dark as you can still see clearly outside.”

If you spend a lot of time driving, Terry recommends gradient lenses, darker at the top and lighter at the bottom. Photosensitive lenses, which darken with exposure to sunlight, can be good, but Terry warns that “they’re not adequate for driving. They work on UV light, and if the windshield blocks those rays, they won’t work adequately.”

Lenses of neutral colors, such as gray, are best “because they put no particular coloration into your vision,” Terry says. “The next choice is dark green or dark brown.”

As far as other colors go, “There’s always a lot of fad-type sunglasses,” Terry says. “Most recently, blue blockers have been popular. But that’s just a fad; it’s not scientifically proven.” Some colored lenses can help in certain situations, however, such as yellow lenses that can make vision better in fog.

When shopping for sunglasses, Gilbreath says, “look through the lens to make sure there’s no distortion. If there’s a line or a place that seems wavy, that’s a problem. If you really want to be sure about it, go to your eye care professional.”

Bittel, for example, offers ophthalmic-quality nonprescription sunglasses for $40 to $80. But if you’re willing to settle for a cheaper frame and lenses that may have minor distortions, you can probably get by for less, say Terry and Gilbreath.

Whatever you do, don’t wear your sunglasses at night. “You’d be surprised; there are a lot of people who do,” Terry says. “They think it helps them with the glare from headlights and other sources. But it really decreases your ability to see.”

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