Welder’s eye, also called arc eye or flash burn, is a painful condition caused by ultraviolet radiation damaging the surface of the eye. It’s essentially a sunburn on the cornea. Symptoms typically appear 6 to 12 hours after exposure and usually resolve within 36 to 72 hours.
How UV Radiation Damages the Cornea
A welding arc produces intense ultraviolet radiation, particularly in the UVB (280–315 nm) and UVC (100–280 nm) wavelength ranges. These shorter wavelengths are the most harmful to the cornea, the clear front layer of the eye. When UV light hits the cornea, it triggers cell death across all three of its layers. This damage can begin after as little as 15 minutes of unprotected exposure, with cell death detectable within about 5 hours.
The medical term for this condition is photokeratitis. It’s not exclusive to welders. Snow glare, tanning beds, and high-altitude sunlight can cause the same injury. But welding arcs are one of the most concentrated sources of UV radiation people encounter at work, making welders and bystanders especially vulnerable.
What It Feels Like
The tricky thing about welder’s eye is the delay. You won’t feel anything during or immediately after exposure. Symptoms typically show up 6 to 12 hours later, which means many people get flashed during a daytime shift and wake up in the middle of the night in serious pain.
The hallmark symptoms include:
- Foreign body sensation: a gritty, sand-in-the-eye feeling that makes you want to rub your eyes (don’t)
- Pain: ranging from mild stinging to intense, throbbing pain in both eyes
- Tearing and redness
- Light sensitivity: even normal room lighting can feel unbearable
- Blurred or decreased vision
In most cases, these symptoms fade within 36 to 72 hours as the cornea regenerates its surface cells. The cornea is one of the fastest-healing tissues in the body, which is why mild to moderate flash burns typically resolve on their own.
Treatment and Pain Relief
Most cases of welder’s eye are managed with comfort measures rather than surgery or intensive treatment. If you visit an emergency department, a doctor will likely use numbing eye drops to examine your eyes, but these drops are only for the exam itself, not for ongoing use at home. Overusing numbing drops actually slows corneal healing.
In some cases, a doctor will use dilating drops that temporarily paralyze the eye’s focusing muscles, letting the eye rest. Your pupils will look noticeably larger than normal, and this effect can last up to 48 hours. Your eyes may also be patched to keep them closed and protected while they heal.
For home care, the main tools are straightforward: over-the-counter pain relievers like paracetamol (acetaminophen) for pain, artificial tears or lubricant drops for comfort, and antibiotic drops or ointment if your doctor prescribes them to prevent infection on the damaged corneal surface. The worst of the pain typically lasts about a day.
Keeping your eyes closed, staying in a dimly lit room, and wearing sunglasses if you need to go outside all help during recovery. Avoid rubbing your eyes, even though the gritty sensation will make that difficult.
When the Injury Is More Serious
While most flash burns heal cleanly, intense or prolonged exposure to a welding arc can damage deeper structures in the eye. Welding radiation doesn’t stop at the cornea. In rare cases, it can reach the retina at the back of the eye and cause maculopathy, which is damage to the central part of the retina responsible for sharp, detailed vision. This type of injury causes decreased visual acuity that may not fully recover.
If your vision remains blurry or distorted after 72 hours, or if you notice a persistent dark spot in the center of your vision, the injury may have gone beyond the cornea. These symptoms warrant prompt evaluation rather than continued home care.
Long-Term Risks of Repeated Exposure
A single flash burn that heals in a few days is unlikely to cause lasting problems. Repeated UV exposure to the eyes over months or years is a different story. UV light ages all structures of the eye, and the cumulative damage is irreversible.
Chronic UV exposure is associated with cataracts, the clouding of the eye’s lens that gradually blurs vision. It’s also linked to macular degeneration, which destroys central vision over time. On the surface of the eye, repeated UV damage raises the risk of pterygium (a fleshy growth that can creep across the cornea) and pinguecula (yellowish bumps on the white of the eye). UV exposure also predisposes the eye’s surface to cancerous growths.
For welders who get flashed occasionally over a long career, these cumulative effects are a real concern. Each episode adds to the total UV load the eye has absorbed.
Prevention and Proper Eye Protection
The right welding helmet with the correct shade lens is the primary defense. OSHA sets minimum shade numbers based on the type of welding and the amperage being used. Higher amperages produce more intense arcs and require darker lenses.
For the most common welding types, here are the OSHA minimums:
- Stick welding (SMAW): Shade 7 for low-amperage work under 60 amps, up to shade 11 for heavy work above 250 amps
- MIG welding (GMAW): Shade 7 below 60 amps, shade 10 for anything from 60 to 500 amps
- TIG welding (GTAW): Shade 8 up to 150 amps, shade 10 above that
- Carbon arc welding: Shade 8 at the low end, up to shade 14 for high-amperage work above 400 amps
These are minimums. Many welders choose one or two shade levels higher for added comfort and protection. Auto-darkening helmets are popular because they allow you to see clearly when positioning your work, then darken instantly when the arc strikes.
Beyond the helmet, wearing safety glasses with UV protection underneath the hood adds a backup layer in case of accidental exposure. Bystanders in the same workspace are often the ones who get flashed, so welding screens or flash curtains around the work area protect everyone nearby. Even a brief, accidental glance at an unshielded arc from across a shop can cause symptoms hours later.