As the holiday season approaches and we prepare to head for beaches and swimming pools, most of us are aware of the danger of the sun’s ultraviolet (UV) radiation on our skins. But there is also a risk of damage to our eyes. Extended exposure to the sun's UV rays has been linked to conditions including cataracts, macular degeneration, and others. While many people refer to ultraviolet radiation as UV light, this is technically incorrect because we cannot see UV rays. There are three categories of UV rays: UVC rays are the most harmful, but fortunately the atmosphere’s ozone layer blocks virtually all of these; UVB rays in low doses stimulate the production of melanin creating a suntan, but in higher doses cause sunburn and premature aging of the skin, and are partially filtered by the ozone layer; UVA rays have the lowest energy but can pass through the cornea, reaching the lens and retina. Outdoor Risk Factors Anyone who spends time outdoors is at risk for eye problems from UV radiation, but this exposure depends on a number of factors. Geographic location. UV levels are greater in tropical areas; the further you are from the equator, the smaller your risk. 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 and sand....
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