Protect your eyes from snow blindness
According to the UV index guide by the US Environmental Protection Agency, UV radiation may be generally lower in winter, but snow reflection can double overall exposure – especially at high altitudes – leading to sunburn and snow blindness.
A research published in the Archives of Dermatology took measurements of UV radiation in 32 high-altitude ski areas in western North America and interviewed 3,937 adult skiers and snowboarders on sun protection. The study found the highest UV radiation level to be at midday as well as during the late winter and early spring (the highest UV rating being at the Mammoth Mountain in California). It was also observed that chances of UV radiation damage were low with adults who used sunscreen and protective eyewear, although fewer did use other sunshields like wearing hats and protective clothing or using lip balm.
Painful sunburn of the eye surface, also known as photokeratitis, is the immediate damage the eyes sustain from excessive sun exposure. This is known as snow blindness if caused by sunlight reflected from ice and snow. Snow reflects about 80% of the UV radiation, and exposure increases with elevation. Eye sunburn may disappear in a few days or lead to complications. Long-term exposure to ultraviolet radiation can cause tumors, macular degeneration (development of blind spots in the eyes), cataracts (clouding of the eye lens) or pterygium (white overgrowth in the eye).
The American Academy of Ophthalmology recommends wearing of protective eyewear that blocks 100 percent of harmful UV rays (UVA and UVB). Eyewear having a “UV400” or “UV protection up to 400nm” label has 100% UV absorption. To be absolutely sure about the UV absorption level of particular eyewear, optometrists can easily measure the lenses using a UV meter device.