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 or less commonly from sea or sand.1 Fresh snow reflects about 80% of the UV radiation compared to a dry, sandy beach (15%) or sea foam (25%). This is especially a problem in polar regions and at high altitudes,2 as with every thousand feet (approximately 305 meters) of elevation (above sea level), the intensity of UV rays increases by four percent.3
Snow blindness is akin to a sunburn of the cornea and conjunctiva, and may not be noticed until several hours after exposure. Symptoms can run the gamut from eyes being bloodshot and teary to increased pain, feeling gritty and swelling shut. In very severe cases, snow blindness can cause permanent vision loss.
To prevent snow blindness, people who are at risk are recommended to use sunglasses that transmit 5-10 % of visible light and absorb almost all UV rays. Additionally, these glasses should have large lenses and side shields to avoid incidental light exposure. Sunglasses should always be worn, even when the sky is overcast as UV rays can pass through clouds.4
If snow blindness does occur, treatment consists of quickly easing the pain with topical anesthetics applied in eye drops and the use of cold wet compresses. Further injury should be avoided by isolation in a dark room, removing contact lenses, not rubbing the eyes, and wearing sunglasses until the symptoms disappear completely.2 There is also an ointment that significantly speeds up recovery.5
In the event of lost or damaged sunglasses, emergency goggles can be made by cutting slits in dark fabric or tape folded back onto itself. The SAS Survival Guide recommends blackening the skin underneath the eyes with charcoal to avoid any further reflection.6
Although not caused by an arc, the identical syndrome of ultraviolet keratitis can be caused by UV from excessive sun exposure, light reflected from snow (known as snow blindness), water or sand. The intense ultraviolet light absorbed by the eye causes a superficial and painful keratitis. 1
Symptoms tend to occur a number of hours after exposure and typically resolve spontaneously within 36 hours. The sensation has been described as like having sand poured into the eyes.
Although it is possible for defects in specific types of industrial lighting to cause the same problem, this phenomenon cannot be caused by simple over-illumination as commonly found in many factory and office environments.
Snow blindness is akin to a sunburn of the cornea and conjunctiva, and may not be noticed until several hours after exposure. Symptoms can run the gamut from eyes being bloodshot and teary to increased pain, feeling gritty and swelling shut. In very severe cases, snow blindness can cause permanent vision loss.
To prevent snow blindness, people who are at risk are recommended to use sunglasses that transmit 5-10 % of visible light and absorb almost all UV rays. Additionally, these glasses should have large lenses and side shields to avoid incidental light exposure. Sunglasses should always be worn, even when the sky is overcast as UV rays can pass through clouds.4
If snow blindness does occur, treatment consists of quickly easing the pain with topical anesthetics applied in eye drops and the use of cold wet compresses. Further injury should be avoided by isolation in a dark room, removing contact lenses, not rubbing the eyes, and wearing sunglasses until the symptoms disappear completely.2 There is also an ointment that significantly speeds up recovery.5
In the event of lost or damaged sunglasses, emergency goggles can be made by cutting slits in dark fabric or tape folded back onto itself. The SAS Survival Guide recommends blackening the skin underneath the eyes with charcoal to avoid any further reflection.6
Also from Wikipedia Arc eye
Arc eye (keratoconjunctivitis photoelectrica), also known as welder's flash, bake eyes, corneal flash burns, or flash burns, is a painful ocular condition sometimes experienced by welders who have failed to use adequate eye protection. It is also referred to as arc flash, though this can also refer to an electrical explosion. It can also occur due to using tanning beds without proper eyewear.Although not caused by an arc, the identical syndrome of ultraviolet keratitis can be caused by UV from excessive sun exposure, light reflected from snow (known as snow blindness), water or sand. The intense ultraviolet light absorbed by the eye causes a superficial and painful keratitis. 1
Symptoms tend to occur a number of hours after exposure and typically resolve spontaneously within 36 hours. The sensation has been described as like having sand poured into the eyes.
Although it is possible for defects in specific types of industrial lighting to cause the same problem, this phenomenon cannot be caused by simple over-illumination as commonly found in many factory and office environments.