Photokeratitis is like sunburn of the eye. Photo means light and keratitis means the inflammation or swelling of the front covering of the eyeball (cornea). Photokeratitis is a painful condition that affects the inside of the eyelids, the cornea and the transparent tissue that covers the white area of the eye (conjunctiva).
Snow blindness is the most common form of this eye disorder. It is particularly prevalent in the high mountains and near the North and South poles.
Also Known As
- UV keratitis
- Radiation keratitis
- Ultraviolet keratitis
- Snow blindness
- Arc eye
- Ultraviolet (UV) burn
Causes and Risk Factors
Photokeratitis is caused by exposure to ultraviolet (UV) rays. These invisible energy rays could be from the sun or artificial sources. UV rays, in particular, UVA and UVB rays from the sun, can damage the eye and affect vision both in the short and long term.
Snow keratitis occurs when UV rays from the sun reflect off water, ice, snow or sand and strike the eyes. It can also develop if a person stares at the sun, for example, observing a solar eclipse without protective gear.
Snow blindness may also occur as a result of the freezing or severe drying of the surface of the cornea due to extreme dryness or cold temperatures. It is more frequent near the North and South poles and in the high mountains because of the thinner air in these regions.
Ultraviolet (UV) burn develops from exposure to UV rays from any the man-made sources. Artificial sources of harmful UV radiations include:
- Mercury vapor lamps
- Welding equipment
- Lights used in tanning booths and beds
- Electric sparks
- Carbon arcs
- Photographic floodlights
- Halogen lighting and desk lamps
Ultraviolet light from arc welding equipment causes the arc eye.
Ultraviolet keratitis risk factors include:
- Skiing and snowmobiling
- Mountain climbing
- Water sports such as surfing, swimming and water-ski
- Hazardous work such as arc welding, photo and film shooting
- Artificial tanning
Use of mercury vapor or halogen lamps and lighting
Signs & Symptoms
Often, photokeratitis, like sunburn is only noticed well after the damage occurs.
The symptoms of UV keratitis may include:
- Eyelid twitching
- Red eyes
- Blurred vision
- Small pupils
- Excess tearing
- A sensation of a foreign object or gritty feeling
- Seeing halos
- Temporary vision loss
- Increased sensitivity to light
- Temporary changes in color vision
- Eye pain
The eye care professional can diagnose photokeratitis through knowledge of the patient’s recent activities and conducting an eye exam to identify the UV damage. He/she may perform a fluorescein test for a definite diagnosis.
Treatment is aimed at making the patient feel better and encouraging corneal healing.
In most cases, photokeratitis goes away without the need for treatment. The eye doctor may prescribe:
- Pain relievers to ease the pain
- Antibiotics eye drops for an eye infection
- Artificial tears for lubricating and moisturizing the eyes
If one experiences any of the UV keratitis symptoms, one should go indoors at once and:
- Stay in a darkened room
- Avoid rubbing the eyes
- Remove contact lenses immediately. Wear them only after the symptoms are gone
- Use a cold compress to soothe eye pain or burning
Resting the eyes away from ultraviolet light is the best way to encourage corneal healing. Often, the symptoms go away in a day or two.
One should seek medical help if there is loss of vision or the symptoms last for more than two days.
Prognosis & Long-Term Outlook
Extended exposure to even small amounts of ultraviolet (UV) radiation, from any source, can boost the chances of developing a cataract. Long-term exposure to solar UV rays increases the risks of developing cataracts or macular degeneration.
People who spend a lot of time outdoors may be more likely to experience photokeratitis.
Prevention & Follow Up
Wearing protective eyewear that blocks ultraviolet (UV) rays may prevent UV keratitis. This may include:
- Sunglasses that absorb or block at least 99 percent of UV rays
- Appropriate goggles for snow and water sports
- Wearing a wide-brimmed hat or visor when outdoors
- Welding helmets
Use of proper protective eye gear for hazardous work