Ultraviolet keratitis, also known as photokeratitis, is a painful eye condition caused by exposure to ultraviolet rays, often from the sun. Ultraviolet keratitis can be compared to a sunburn, except that it affects the corneas of the eyes instead of the skin. Exposure to ultraviolet rays can temporarily damage the cornea (the clear portion of the eye in front of the pupil) and the conjunctiva (a layer of cells covering the inside of the eyelid and the whites of the eye). Damage to the eyes can occur following exposure to sunlight reflected by snow, ice, water, or sand. Staring directly at the sun, such as during a solar eclipse, can also damage the eyes.
Snow blindness is a type of ultraviolet keratitis that occurs when UV rays are reflected by snow and ice. It is more common near the North and South Poles or in mountainous regions where the air is thinner.
Symptoms may include:
The symptoms may last from 6 to 24 hours, but they usually disappear within 48 hours.
Ultraviolet rays from the sun or other sources can damage the eyes. In particular, UV-A and UV-B rays from the sun can cause short- and long-term damage to the eyes and affect vision. Although the sun also emits UV-C radiation, those rays are absorbed by the ozone layer and do not damage the eyes. Harmful ultraviolet radiation can also be emitted by lasers, mercury vapor lamps, lamps used in tanning beds or booths, and welding equipment. Other sources include carbon arcs, photographic flood lamps, electric sparks, halogen desk lamps, and lightning.
Long-term exposure to even small amounts of UV radiation can increase the risks of developing a cataract. The risks of developing cataracts or macular degeneration increase the longer one is exposed to solar UV rays.
People who spend a lot of time outdoors -- such as mountain climbers, hikers, and swimmers -- may be more likely to experience ultraviolet keratitis.
You doctor will examine your eyes and ask you questions about your recent activities. An ophthalmologist (doctor who specializes in eye problems) can determine how much damage has occurred by examining the eyes. The doctor may place drops containing a dye called fluorescein into the eyes. The dye can reveal superficial irregularities on the surface of the cornea.
If you experience symptoms, go indoors immediately. Stay in a darkened room. Remove your contact lenses if you wear them. Do not rub your eyes.
Sometimes a cold washcloth placed over the eyes can help relieve discomfort. Taking an over-the-counter non-steroidal anti-inflammatory pain reliever can also help.
Usually the condition goes away on its own within a few days. If medical treatment is necessary, the doctor may prescribe eye drops if there is a risk of eye infection.
Seek medical attention if you experience a loss of vision or pain that lasts for more than 2 days.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition. This document was last reviewed on: 04/25/2015