ⓘ Photokeratitis or ultraviolet keratitis is a painful eye condition caused by exposure of insufficiently protected eyes to the ultraviolet rays from either natur ..

                                     

ⓘ Photokeratitis

Photokeratitis or ultraviolet keratitis is a painful eye condition caused by exposure of insufficiently protected eyes to the ultraviolet rays from either natural or artificial sources. Photokeratitis is akin to a sunburn of the cornea and conjunctiva, and is not usually noticed until several hours after exposure. Symptoms include increased tears and a feeling of pain, likened to having sand in the eyes.

The injury may be prevented by wearing eye protection that blocks most of the ultraviolet radiation, such as welding goggles with the proper filters, a welders helmet, sunglasses rated for sufficient UV protection, or appropriate snow goggles. The condition is usually managed by removal from the source of ultraviolet radiation, covering the corneas, and administration of pain relief. Photokeratitis is known by a number of different terms including: snow blindness, arc eye, welders flash, bake eyes, corneal flash burns, sand mans eye, flash burns, niphablepsia, potato eye, or keratoconjunctivitis photoelectrica.

                                     

1. Cause

Any intense exposure to UV light can lead to photokeratitis. Common causes include welders who have failed to use adequate eye protection such as an appropriate welding helmet or welding goggles. This is termed arc eye, while photokeratitis caused by exposure to sunlight reflected from ice and snow, particularly at elevation, is commonly called snow blindness. It can also occur due to using tanning beds without proper eyewear. Natural sources include bright sunlight reflected from snow or ice or, less commonly, from sea or sand. 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, as with every thousand feet approximately 305 meters of elevation above sea level, the intensity of UV rays increases by four percent.

                                     

2. Prevention

Photokeratitis can be prevented by using sunglasses or eye protection that transmits 5–10% of visible light and absorbs 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.

The Inuit, Yupik, and other Arctic peoples carved snow goggles from materials such as driftwood or caribou antlers to help prevent snow blindness. Curved to fit the users face with a large groove cut in the back to allow for the nose, the goggles allowed in a small amount of light through a long thin slit cut along their length. The goggles were held to the head by a cord made of caribou sinew.

In the event of missing sunglass lenses, emergency lenses 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 as the ancient Egyptians did to avoid any further reflection.

                                     

3. Treatment

The pain may be temporarily alleviated with anaesthetic eye drops for the examination; however, they are not used for continued treatment, as anaesthesia of the eye interferes with corneal healing, and may lead to corneal ulceration and even loss of the eye. Cool, wet compresses over the eyes and artificial tears may help local symptoms when the feeling returns. Nonsteroidal anti-inflammatory drug NSAID eyedrops are widely used to lessen inflammation and eye pain, but have not been proven in rigorous trials. Systemic oral pain medication is given if discomfort is severe. Healing is usually rapid 24–72 hours if the injury source is removed. Further injury should be avoided by isolation in a dark room, removing contact lenses, not rubbing the eyes, and wearing sunglasses until the symptoms improve.

                                     
  • magnitude. Damage to the eye s caused by ultraviolet rays is known as photokeratitis Karmakar, RN. Forensic Medicine and Toxicology. Academic Publishers
  • lower UV absorption - is the main cause of the injury. Conjunctivitis Photokeratitis Dorland s Medical Dictionary confabulation - connexus Archived
  • Snowblind or Snow Blind may refer to: Snow blindness or photokeratitis a type of temporary eye damage caused by snow reflecting UV light Snow Blind film
  • welding is going on can result in a painful condition called arc eye or photokeratitis which is akin to a severe sunburn of the cornea and conjunctiva of
  • caused by incomplete or inadequate eyelid closure lagophthalmos Photokeratitis - keratitis due to intense ultraviolet radiation exposure e.g. snow
  • Corneal ulcer H16.1 Other superficial keratitis without conjunctivitis Photokeratitis Snow blindness H16.2 Keratoconjunctivitis H16.3 Interstitial and
  • UVA does not cause immediate reaction, but rather UV begins to cause photokeratitis and skin redness with Caucasians more sensitive at wavelengths starting
  • radiation and health Light: see Laser safety Ultraviolet UV see Sunburn, Photokeratitis Gamma rays: see Gamma ray Afterglow plasma Antenna factor Classification
  • of the immune system, and damage to the eyes, including cataracts, photokeratitis snow blindness and eye cancer. Injuries caused by tanning devices
  • cause damage to the eyes and skin including photoconjunctivitis and photokeratitis Researchers have questioned whether limiting blue light exposure could
  • to the cornea, known as arc eye or welding flash burn, a form of photokeratitis Fluorescent light bulbs and tubes internally produce ultraviolet light
  • to tie themselves to their sledges as a precaution. Ninnis developed photokeratitis snow - blindness which Mawson treated with zinc sulfate and cocaine
  • pharmaceutical called Benzedrine in tablet form. Eyton - Jones suffered Photokeratitis a temporary blindness caused by sunlight reflecting from the snow.