Snow blindness

Snow blindness

Infobox_Disease
Name = PAGENAME


Caption =
DiseasesDB = 31147
ICD10 = ICD10|H|16|1|h|15
ICD9 = ICD9|370.24
ICDO =
OMIM =
MedlinePlus =
eMedicineSubj = emerg
eMedicineTopic = 759
MeshID =

Snow blindness (Niphablepsia) is a painful condition, typically a keratitis, caused by exposure of unprotected eyes to the ultraviolet (UV) rays in bright sunlight reflected from snow or ice. This is especially a problem in polar regions and at high altitudes, as with every thousand feet (approximately 305 meters) increase in elevation, the intensity of UV rays goes up five percent.

The problem is also related to the condition arc eye sometimes experienced by welders.

Snow blindness is akin to a sunburn of the cornea and conjunctiva, and may not be noticed for several hours from 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.

The Inuit carved goggles from caribou antler to help prevent snow blindness. The goggles were curved to fit the user's face and had a large groove cut in the back to allow for the nose. A long thin slit was cut through the goggles to allow in a small amount of light. The goggles were held to the head by a cord made of caribou sinew.

Prevention

When trekking, mountaineering or skiing, sunglasses that offer the following are frequently recommended:

* 99-100% UV absorption
* Polycarbonate or CR-39 lens
* 5-10% visible light transmittance
* Large lenses that fit close to the face and cover the whole eye
* Wraparound, side-shielded, or dark-lensed 'glacier' glasses to prevent incidental light exposure
* Wear even when the sky is overcast, as UV rays can still filter through clouds
* In the event of lost or damaged sunglasses, make emergency goggles by cutting slits in dark fabric or tape folded back onto itself

Treatment

Following these guidelines will allow the pain and symptoms of snow blindness to disappear as the cornea heals:

* Avoid rubbing eyes and remove contact lenses
* Administer an oral pain medication such as ibuprofen
* Cover eyes with soft thick cloth pads or gauze bandages to prevent irritation from eyelid movement and protect from light; rest in a dark room if possible
* Apply cold wet compresses to ease burning sensations
* Check injury at half-day intervals; remove dressing when eyes can remain open comfortably
* Wear sunglasses outside until symptoms completely disappear

ee also

*Albedo
*Glare (vision)
*Over-illumination
*Winter sport
*Sunglasses

External links

* [http://www.basecampmd.com/expguide/snowblind.shtml Everest Base Camp Clinic - Eye Concerns at Altitude]
* [http://www.mounteverest.net/expguide/snowblind.htm Mount Everest.net - Snow Blindness]
* [http://www.gpnotebook.co.uk/cache/-268042203.htm General Practice Notebook - Snow Blindness]
* [http://www.sherpatrek.com/pemas_stories/pemas-snow-blind.php An Experience of Snow Blindness]
* [http://www.athropolis.com/arctic-facts/fact-goggles.htm Historical Snow Goggles]


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Look at other dictionaries:

  • snow blindness — n inflammation and photophobia caused by exposure of the eyes to ultraviolet rays reflected from snow or ice * * * a painful disorder of the cornea of the eye due to excessive exposure to ultraviolet light reflected from the snow. Recovery… …   Medical dictionary

  • snow blindness — snow .blindness n [U] eye pain and difficulty in seeing things, caused by looking at snow in bright light from the sun >snow blind adj …   Dictionary of contemporary English

  • snow blindness — noun : inflammation and photophobia caused by exposure of the unprotected eyes to ultraviolet rays reflected from fields of snow or ice suffering the excruciating agony of snow blindness after two weeks of futile searching in the empty plains… …   Useful english dictionary

  • Snow-blindness — Snow blind Snow blind , a. Affected with blindness by the brilliancy of snow. {Snow blind ness}, n. [1913 Webster] …   The Collaborative International Dictionary of English

  • snow blindness — snow′ blind ness n. oph the usu. temporary blindness caused by the glare of reflected sunlight on snow snow′ blind , adj …   From formal English to slang

  • snow blindness — snow blind /snoh bluynd /, adj. the usually temporary dimming of the sight caused by the glare of reflected sunlight on snow. [1740 50] * * * …   Universalium

  • snow-blindness — noun temporary blindness caused by exposure to sunlight reflected from snow or ice • Syn: ↑snowblindness • Derivationally related forms: ↑snow blind (for: ↑snowblindness) • Hypernyms: ↑blindness, ↑ …   Useful english dictionary

  • snow blindness — noun Date: 1748 inflammation and photophobia caused by exposure of the eyes to ultraviolet rays reflected from snow or ice • snow blind or snow blinded adjective …   New Collegiate Dictionary

  • snow blindness — noun (U) eye pain and difficulty in seeing things, caused by looking at snow in bright sunlight snow blind adjective …   Longman dictionary of contemporary English

  • snow blindness — /ˈsnoʊ blaɪndnəs/ (say snoh bluyndnuhs) noun conjunctivitis and deteriorated vision caused by reflection of strong light on snow or ice. –snow blind, adjective …  

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