What is photokeratitis?
Photokeratitis is a painful, temporary eye condition caused by exposure to ultraviolet (UV) rays, most commonly from the sun. Photokeratitis can be compared to a sunburn, except that it affects the cornea of your eyes instead of your skin. Exposure to UV rays can temporarily damage the cornea (the clear part of your eye in front of your pupil) and conjunctiva (a clear layer of tissue that covers the inside of your eyelid and the white of your eye).
Snow blindness is a type of photokeratitis that occurs when UV rays are reflected by snow and ice. It is most common near the North and South Poles or in mountainous areas where the air is thinner and provides less protection from UV rays.
Who is most at risk of developing photokeratitis?
You are at greater risk of getting photokeratitis if:
- You spend a lot of time outdoors in the sun - taking part in activities such as hiking, climbing, skiing and swimming.
- Using a lamp, tanning bed or when working or spending time in environments where there is a source of ultraviolet light.
- Live at higher altitudes (greater exposure to UV rays) or in the sunbelt.
What causes photokeratitis;
Your eyes can be damaged by UV rays. Specifically, UV-A and UV-B rays from the sun can cause short- and long-term damage to your eyes and affect your vision. Although the sun also emits UV-C radiation, these rays are absorbed by the ozone layer and do not harm your eyes.
In addition to direct sunlight, other sources of UV light that can cause photokeratitis include:
- Sunlight reflected into your eyes from snow, ice, water, sand or cement.
- Lamps used in tanning beds or tanning booths .
- Laser lights
- Hydrogen vapour lamps, halogen table lamps.
- Missiles, electric sparks.
- Arc welding equipment, photographic flood lamps.
Looking directly at the sun, such as during a solar eclipse, can actually cause more long-term and serious damage - burns - to your retina.
What are the symptoms of photokeratitis?
If you have photokeratitis, you may experience one or more of the following symptoms:
- .
- Pain or redness in the eyes .
- Sharp/ watery eyes .
- blurred vision
- Puffiness
- Sensitivity to light
- Contraction of eyelids
- Sensitivity of hair in the eyes
- Temporary loss of vision
- Headaches
- Temporary loss of vision (rare)
- Colour changes in your vision (rare)
Symptoms can last from 6 to 24 hours, but usually disappear within 48 hours. The longer you are exposed to UV radiation, the more severe your symptoms may be.
How can photokeratitis be prevented?
- Protect your eyes with sunglasses or snow goggles. Sunglasses or glasses that block or absorb 99% to 100% of UV rays are recommended if you spend time outdoors. Wraparound sunglasses or those with side panels are recommended to block all harmful UV rays. The glare from snow, sand or water can cause eye burns even if it's cloudy or overcast.
- Wear a wide-brimmed hat or visor when going outdoors.
- Wear appropriate eye protection if you are exposed to UV radiation at work.
- If you wear contact lenses and work or play in a sunny environment, ask your eye doctor about UV-absorbing contacts.
- Visit your eye doctor at least once a year for a complete eye exam.
