The UV exposure from skiing on fresh snow, skating on reflective ice or even sledding can be higher than a day at the beach. Snow reflects nearly 80 percent of the sun’s rays while beach sand reflects just 15 percent.
“Most people don’t appreciate the damage that UV rays can do to their eyes,” said Karla Zadnik, OD, PhD, medical director of Realeyes, and associate dean at The Ohio State University College of Optometry.
Over time, unprotected exposure to sunlight can burn the eye, causing damage to the cornea, lens, and retina, and can lead to cataracts and cancer of the eyelids and the skin around the eyes. In high, short-term doses, UV rays also can cause photokeratitis or “snow blindness,” a painful inflammation of the cornea causing temporary vision loss. The risk for snow blindness is greatest at high altitudes, but it can occur anywhere there is snow without UV protection.
A few things to remember about UV levels:
• Altitude: UV levels are greater at higher altitudes.
• Time of day: UV levels are greater when the sun is high in the sky, typically from 10 a.m. to 2 p.m.
• Setting: UV levels are greater in wide-open spaces, especially when highly reflective surfaces are present, like snow. In fact, UV exposure can nearly double when UV rays are reflected from the snow. There is less risk of UV exposure in urban settings, where tall buildings shade the streets.
Cloud cover does not affect UV levels significantly; meaning the risk of UV exposure is still quite high on hazy or overcast days. This is because UV is invisible radiation, not visible light, and can penetrate clouds.
Zadnik said the effects of sunlight exposure are cumulative. “Wear UV-protective sunglasses to reduce the amount of light entering the eye, but don’t let price and style be your only guide when choosing sunglasses. Some cheap sunglasses are great, and some expensive ones are not,” she said.
Glasses with dark lenses but no UV protection may harm your eyes because the tinted lenses relax your pupils and allow damaging radiation to get to your retina. Look for sunglasses or goggles that provide at least 98 percent UV protection; the darkness of the lens does not matter. While most people take measures to protect their skin against the harmful rays of the sun, many fail to realize the effects of the sun on their eyes.
It’s especially important for children to wear protective sunglasses, Zadnik said. They generally spend more time outdoors and their lenses are clearer, meaning more light gets into the eye. Experts say as much as 80 percent of lifetime exposure to UV rays occurs before age 18.
In order to educate children on the importance of vision health and eye safety, the Ohio Optometric Association created Realeyes, a program where local eye doctors present an age-appropriate curriculum in schools, libraries, and summer camps. The 45-minute lessons include hands-on activities about the importance of vision health and eye protection. Now in its 11th year, Realeyes has been presented to 450,000 students in schools throughout Ohio. Funds for Realeyes are provided through the Ohio Department of Health Save Our Sight program. When renewing license plates, Ohioans are asked to donate to Save Our Sight, which funds various programs that deal with children’s vision.
To schedule the Realeyes Classroom Initiative, contact Matt Fink at 614-781-0708, e-mail at mfink@ooa.org, or visit http://www.ooa.org.
Published: February 22, 2011









