Monday Medical: For your eyes, only the best will do
June 23, 2008
People wear sunglasses for a variety of reasons. Poker players use them to conceal their eyes and intimidate the opposition. Celebrities wear them to thwart the paparazzi. Those of us who are not famous at least hope we look cool in “shades.”
But the primary purpose of sunglasses is to protect our eyes.
“Think of sunglasses as sunscreen for your eyes,” Dr. Mark Helm of Helm Eye Center in Steamboat Springs said. “It’s important to protect your eyes from the sun because there are a multitude of things that can hurt you.
“Some are surface problems, such as sunburn of the cornea, called radiation keratitis or snow blindness,” he added. “That can be acutely painful. We’ll see that especially in the spring when people are skiing and take their sunglasses off for a while.”
Symptoms, which develop six to 12 hours after exposure, include pain, headache, a gritty feeling in the eyes, halos around lights, hazy vision or even temporary blindness. Treatment with a topical medicine usually takes care of the pain, Helm noted.
Other damage caused by bright sunlight can be serious and even permanent. Cataracts, macular degeneration and abnormal growths on the eyes have been linked to excessive UV exposure.
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“Cataracts are common, and about 20 percent of the cases we see are probably due to UV radiation,” Helm said. “Ranchers who have been out in the field their whole lives are vulnerable. Cataracts can lead to loss of vision if not treated surgically.”
Intense or long-term exposure to UV radiation is one risk factor for macular degenerative disease, Helm said. This is a permanent condition involving damage to the central part of the retina, the lining at the back of the eye that is crucial to vision. Macular degenerative disease is a major cause of blindness among persons age 50 and older.
Growths on the eye caused by UV radiation do not cause vision problems, but they can lead to a permanent disfiguration, Helm said.
“These growths are like a callus on the white part of the eye. They are ugly and make the eye seem bloodshot,” he added. “I see teenagers who already have growths starting. The problem has to be advanced before I would offer surgery, so people just live with it.”
The American Academy of Ophthalmology recommends that people protect their eyes year-round by wearing sunglasses that block 97 to 100 percent of UV and UV-B rays. Labels are not mandatory, so look for a brand that declares the protection level. The academy recommends wrap-around styles that block light from the sides.
If you already wear glasses, you might want to consider photochromic or “Transition” lenses that automatically become darker or lighter according to the amount of light exposure. I have been wearing these lenses for almost two years, and I love them.
I got tired of lugging around prescription sunglasses and constantly switching between my regular glasses and shades. After losing a couple of pairs of expensive prescription sunglasses, I chose to invest in a pair that I never need to change.
A new advance is the “Drivewear” brand that will darken your lenses inside a vehicle or near a window in your home, even if the windows are tinted. Glasses don’t need to turn dark for over protection; a clear UV-blocking coating can be added to new eyeglasses.
Some contact lenses come with UV protection, but be aware that contacts cover only the lens, leaving the rest of the eye vulnerable to damage.
If you need one more reason to protect your eyes, Helm is happy to supply it.
“Sunglasses can help you prevent skin cancer around your eyes,” he says. “Cancers can grow on the eyelids and even the surface of the eyes. This is a nasty problem and can be very difficult to treat.”
UV rays are most intense from 10 a.m. to 3 p.m. and during the months of May through August. But there is a danger to the eyes and skin any time, even when it is cloudy. Snow, water and pavement can intensify whatever UV rays are present.
It is a very good idea to respect the environment and protect yourself by getting a good pair of sunglasses and wearing them regularly. In other words, stay in the shades.