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 corneas of your eyes instead of your skin. Exposure to ultraviolet rays can temporarily damage your cornea (the clear portion of your eye in front of your pupil) and the conjunctiva (a clear layer of tissue covering the inside of your eyelid and the whites of your eye).
Snow blindness is a type of photokeratitis 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 and provides less protection against UV rays.
Who is most at risk for getting photokeratitis?
You’re at greater risk of getting photokeratitis if you:
- Spend a lot of time outdoors in the sun – engaging in activities such as mountain climbing, hiking, skiing, and swimming.
- Use a sunlamp, tanning bed, or work or spend time in environments in which there is UV light source.
- Live in higher altitudes (greater exposure to UV rays) or in the sunbelt.
Symptoms and Causes
What causes photokeratitis?
Your eyes can be damaged from ultraviolet rays. In particular, 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, those rays are absorbed by the ozone layer and don’t damage your eyes.
Besides direct sunlight, other sources of ultraviolet light that can cause photokeratitis include:
- Sunlight that’s reflected into your eyes from snow, ice, water, sand or cement.
- Lamps used in tanning beds or booths.
- Laser light.
- Mercury vapor lamps, halogen desk lamps.
- Lightning, electric sparks.
- Arc welding equipment, photographic flood lamps.
Staring directly at the sun, such as during a solar eclipse, can actually cause more long lasting and serious damage – a burn – 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.
- Tearing/watery eyes.
- Blurry vision.
- Light sensitivity.
- Twitching of the eyelids.
- Gritty sensation in the eyes.
- Temporary loss of vision.
- Seeing halos.
- Temporary vision loss (rare).
- Color changes in your vision (rare).
The symptoms may last from six to 24 hours, but they usually disappear within 48 hours. The longer you’re exposed to UV light, the more severe your symptoms might be.
Are there other complications of UV ray exposure?
Long-term exposure to even small amounts of UV radiation can increase your risk of developing a cataract or macular degeneration. UV exposure adds up over time. Long-term UV exposure can also causes tissue elevations on the surface of your eye. These are called pingueculae and pterygia. Using sunglasses faithfully when outdoors may limit these.
Blue and violet shorter-wavelength visible light, emitted from LED lights, computers and smartphones can also be harmful to your retina and be a risk factor for macular degeneration later in life.
Diagnosis and Tests
How is photokeratitis diagnosed?
Your eye doctor will examine your eyes and ask you questions about your recent activities and work environment. An ophthalmologist (doctor who specializes in eye problems) can determine if and how much damage has occurred to your eyes. Your doctor may place drops containing a dye called fluorescein into your eyes. The dye helps reveal superficial irregularities on the surface of your cornea.
Management and Treatment
How is photokeratitis treated?
If you experience symptoms, go indoors immediately. Stay in a darkened room. Remove your contact lenses if you wear them. Don’t rub your eyes.
To relieve your discomfort, place a cold washcloth over the closed eyes, use artificial tears, and/or take an oral over-the-counter nonsteroidal anti-inflammatory drug like ibuprofen (Advil®, Motrin®).
Usually the condition goes away on its own within a few hours to days. If medical treatment is necessary, your 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 two days.
How can photokeratitis be prevented?
- Wear proper eye protection such as sunglasses or snow goggles. Sunglasses or goggles that block or absorb 99% to 100% of UV rays are recommended if you spend time outdoors. Wrap-around sunglasses or those with side panels are recommended to block all harmful UV rays. Glare from the snow, sand or water can cause burns to the eyes even if it is cloudy or overcast.
- Wear a wide-brimmed hat or visor when you go outdoors.
- Use proper eye protective equipment if you are exposed to UV radiation on the job.
- If you wear contact lenses and work or play in a sunny environment, ask your eye care specialist about UV absorbing contacts.
- See your eye care specialist at least once a year for a complete eye exam.
Outlook / Prognosis
What can I expect if I have photokeratitis?
The good news about photokeratitis is that it's a temporary condition and your symptoms usually go away within a few hours to a couple days. You can relieve most symptoms with at-home remedies. Preventing photokeratitis is easy -- always wear sun glasses or other eye protection that blocks or absorbs UV rays when outside (even on cloudy days) or exposed to certain light sources used at your job. Visit your eye specialist once a year to stay up on your eye health and catch any eye problems early.