Photokeratitis, commonly known as arc eye or welder’s flash, is a temporary but often painful eye condition resulting from unprotected exposure to intense ultraviolet (UV) radiation. It is akin to a sunburn on the eye’s surface, specifically affecting the cornea, the clear front part of the eye, and the conjunctiva. It is also referred to as snow blindness when caused by reflective surfaces in snowy environments.
The Sensation and Symptoms
The discomfort associated with arc eye typically appears 30 minutes to 12 hours after exposure. This delay often means individuals may wake up in the middle of the night experiencing symptoms. Many describe a gritty, sandy sensation, burning, and intense pain.
The pain can be severe enough to make it difficult to work, drive, or sleep. Other noticeable symptoms include heightened sensitivity to light (photophobia), which can lead to headaches. The eyes may become watery, appear red, and the eyelids might swell. Vision can also become blurry, and some individuals report seeing halos around lights or temporary vision loss.
Common Causes
Arc eye results from UV radiation damaging the delicate surface cells of the cornea and conjunctiva, similar to how skin gets sunburned. A primary source of this harmful radiation is the intense light produced during welding, which is why the condition is frequently called welder’s flash or arc eye.
Natural culprits include sunlight reflecting off highly reflective surfaces such as snow, ice, water, or sand, particularly common at high altitudes. Artificial sources also contribute, including sunlamps, tanning beds, and germicidal UV lamps. Other less common sources are mercury vapor lamps, halogen lamps, lasers, and photographic flood lamps.
Seeking Relief and Recovery
If arc eye is suspected, immediate actions can help manage discomfort. It is advisable to remove any contact lenses and refrain from rubbing the eyes, as this can worsen irritation and inflammation. Resting in a dark room and avoiding bright lights can also provide significant relief.
For symptom management, apply cold compresses or a cool, moist washcloth over closed eyes. Over-the-counter pain relievers, such as aspirin or ibuprofen, can help alleviate pain. Artificial tears may also be used to soothe the eyes. While many cases resolve on their own, medical attention is recommended if symptoms are severe or persist, to ensure proper care. A doctor might prescribe antibiotic eye drops to prevent infection, steroid drops to reduce inflammation, or cycloplegic drops to relax eye muscles and ease pain. Arc eye is typically a temporary condition, with most symptoms resolving within 24 to 48 hours.
Preventing Arc Eye
Protecting the eyes from harmful UV radiation is the most effective way to prevent arc eye. For activities involving welding, specialized welding helmets or goggles are essential, designed to provide 100% protection against both UV and infrared (IR) rays. These protective devices should meet safety standards, such as ANSI Z87.1.
For general outdoor exposure, especially in environments with reflective surfaces like snow or water, wearing sunglasses that block 100% of both UVA and UVB rays is recommended. Many sunglasses are labeled as providing “100% UV protection” or “UV400.” These glasses should ideally feature large lenses and side shields to prevent UV light from entering from the periphery. Wearing protective eyewear is important even on cloudy days, as UV rays can still penetrate cloud cover.