How is snow blindness caused?

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Hint: Snow blindness is also called photokeratitis or ultraviolet keratitis is a painful eye condition. Symptoms include eye discomfort, pain, intense tears, eyelid twitching, discomfort from bright light, and pupils constricted.

Complete answer: The condition of snow blindness is caused by exposure of not sufficiently protected eyes to the ultraviolet (UV) rays from natural light example; intense sunlight or can be an artificial source example; the electric arc during welding. Photokeratitis is similar to a sunburn of the cornea and conjunctiva of the eye. It is usually noted after several hours of exposure to UV. Symptoms include increased tears and pain feels like sand in the eyes.
The causes of snow blindness are as follows:
1. Strong exposure to UV light.
2. Commonly occurs to the welders who fail to use inadequate eye protection such as a suitable welding helmet or welding goggles. This is termed arc eye.
3. Photokeratitis caused by exposure to light reflected from snow and ice, particularly at altitude, is commonly called snow blindness. It can also occur due to using tanning beds deprived of proper eyewear.
4. Natural sources consist of bright sunlight reflected from snow or ice and rarely from sea or sand. Fresh snow reflects about 80% of the UV radiation compared to a dry, sandy beach reflects about 15%, and seafoam about 25%.
5. This is particularly a problem in Polar Regions and at high altitudes, as with every thousand feet of height (above sea level), the intensity of UV rays increases by 4%.

Note: Snow reflects 80% of UV radiation playing in the snow for several hours without wearing proper eyeglasses can cause temporary blindness hence it is known as snow blindness. Condition is accompanied by severe eye pain. After proper medications and care, healing is quick, usually 24 to 72 hours.