Welding exposes the eyes to intense radiation, including ultraviolet (UV), visible light, and infrared (IR) rays, which can cause injury quickly. The most common acute injury, often called arc eye or welder’s flash, can occur after just a few seconds of unprotected exposure. While this immediate damage is intensely painful, it rarely leads to permanent blindness. Lasting vision loss is linked to chronic, cumulative exposure or a single, severe incident that allows high-energy light to penetrate the back of the eye. Proper protective gear is the only defense against both the rapid, temporary injury and the slower, permanent risks.
The Mechanism of Acute Arc Eye (Photokeratitis)
Acute damage from welding, medically known as photokeratitis, is essentially a painful sunburn on the clear front surface of the eye. This injury is caused by the intense ultraviolet (UV) radiation emitted by the electric arc, which is significantly more powerful than the UV rays from the sun. The cornea, the transparent outer layer of the eye, absorbs the majority of this harmful UV light.
Damaging exposure can happen very quickly; an unprotected glimpse of the arc for only a few seconds is sufficient to injure the corneal tissue. The injury is immediate, but the symptoms are characteristically delayed because UV exposure temporarily desensitizes the cornea. It takes time for the damaged epithelial cells to die and slough off.
Typically, severe discomfort begins six to twelve hours after exposure, often waking the person at night. Symptoms include severe pain, a gritty sensation, excessive tearing, and sensitivity to light (photophobia). Although distressing, this surface injury generally heals without permanent vision loss.
Is Permanent Blindness a Risk? (Long-Term Chronic Effects)
While a single episode of arc eye rarely results in permanent blindness, chronic or severe exposure to welding radiation can cause lasting vision impairment. The intense light and radiation affect different parts of the eye, leading to distinct long-term risks involving the lens and the retina.
One significant chronic risk is the development of cataracts, a clouding of the eye’s lens. This is caused by the cumulative effects of long-term exposure to UV radiation and infrared (IR) radiation, which can heat the lens over time. Cataracts gradually impair vision and are a leading cause of preventable blindness worldwide.
A rarer, yet more severe, risk is permanent damage to the retina. This occurs from extremely intense visible light or high-energy IR radiation that penetrates the lens and reaches the light-sensitive macular area. This thermal injury can cause an irreversible permanent blind spot or severely reduced central vision. Welders who briefly strike an arc before the helmet darkens or use an inadequate shade risk this deep, focused burn.
Recovery and Immediate Care for Eye Injuries
When symptoms of photokeratitis begin, avoid rubbing the eyes, as this can cause further damage to the compromised corneal surface. Applying a cold compress or a cool washcloth over the closed eyes helps alleviate pain and reduce swelling. It is also helpful to rest the eyes and remain in a dark environment to minimize light sensitivity.
For immediate relief and to promote healing, over-the-counter pain relievers, such as nonsteroidal anti-inflammatory drugs (NSAIDs), and preservative-free artificial tears can be used. Photokeratitis is typically a temporary, self-limiting condition that resolves completely within 24 to 48 hours as the corneal epithelial cells regenerate.
Medical attention should be sought if the pain is severe, persists beyond 48 hours, or if there is any significant change in vision. A doctor may prescribe a topical antibiotic drop to prevent a secondary infection or a cycloplegic agent to relieve painful ciliary muscle spasms. Note that while topical anesthetic drops instantly relieve pain, they are avoided because they can slow the healing process.
Essential Protective Measures for Welders
Preventing eye injury from welding hinges entirely on using the correct personal protective equipment (PPE) for every task. The most important gear is the welding helmet, which must be equipped with a filter lens that blocks virtually all UV and IR radiation. Standard welding processes require a filter lens with a shade number of 10 or higher.
The shade number indicates the darkness, with higher numbers filtering out more light. The correct level is determined by the welding process and the current being used. For example, high-amperage processes often require shades up to 14 for adequate protection.
Auto-darkening helmets are effective, as they automatically switch from a light shade to a dark protective shade within milliseconds of detecting the arc. Welders should also wear approved safety glasses with side shields underneath the helmet. This protects against flying debris, metal splatter, and grinding fragments. Bystanders and anyone working nearby must also be protected, as the arc’s radiation can injure eyes up to 50 feet away.