Snow Blindness
Fresh snow reflects 90% or more of ultraviolet radiation, which causes snow blindness, also reducing absorption of sunlight by the ground. Snow blindness (also known as ultraviolet keratitis, photokeratitis or niphablepsia) is a painful eye condition, caused by exposure of unprotected eyes to the ultraviolet (UV) rays in bright sunlight reflected from snow or ice. This condition is a problem in polar regions and at high altitudes, as with every 1,000 feet (300 m) of elevation (above sea level), the intensity of UV rays increases by 4%. Snow's large reflection of light makes night skies much brighter, since reflected light is directed back up into the sky. However, when there is also cloud cover, light is then reflected back to the ground. This greatly amplifies light emitted from city lights, causing the 'bright night' effect. A similar brightening effect occurs when no snow is falling and there is a full moon and a large amount of snow.
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Famous quotes containing the words snow and/or blindness:
“long long
The snow has possessed the mountains.”
—Unknown. The Grass on the Mountain (l. 1–2)
“It is unheard-of, uncivilized barbarism that any woman should still be forced to bear such monstrous torture. It should be remedied. It should be stopped. It is simply absurd that, with our modern science, painless childbirth does not exist as a matter of course.... I tremble with indignation when I think of ... the unspeakable egotism and blindness of men of science who permit such atrocities when they can be remedied.”
—Isadora Duncan (1878–1927)