Welder’s flash, also known as arc eye or photokeratitis, is a common and intensely painful eye condition resulting from unprotected exposure to the powerful light produced by arc welding. This temporary injury is essentially a sunburn on the surface of the eye. While the symptoms are severe, the condition is usually self-limiting and rarely leads to long-term vision problems. Understanding the injury mechanism and expected healing timeline can help manage the associated anxiety.
The Causes of Welder’s Flash
The injury is scientifically classified as photokeratitis, which is the inflammation of the cornea caused by ultraviolet (UV) radiation. A welding arc emits an intense burst of electromagnetic radiation across the full UV spectrum, including the damaging UV-B and UV-C wavelengths. When the eye is exposed without proper shielding, the UV energy is absorbed by the cornea, the clear, outermost layer of the eye. This absorption damages the corneal epithelium, the superficial layer of cells covering the cornea.
This damage causes the epithelial cells to die and slough off, leaving the delicate nerve endings underneath exposed and irritated. The injury is comparable to a severe sunburn, but the pain is often more acute because the cornea is densely packed with sensory nerves. The intensity of the injury depends on both the duration of exposure and the strength of the welding arc.
What Symptoms to Expect
The most distinctive feature of welder’s flash is the delayed onset of symptoms, which typically begin six to twelve hours after exposure, often waking the person up at night. The primary symptom is severe, sharp eye pain, often described as a burning or scratchy sensation, as if a foreign body is lodged in the eye.
This pain is accompanied by intense light sensitivity (photophobia), making it difficult to open the eyes in moderately lit environments. Affected individuals also experience excessive tearing (lacrimation), and the eyes appear noticeably red and bloodshot. Vision may be temporarily blurred due to the disruption of the corneal surface and the excessive watering.
The Duration of Recovery
The corneal epithelium possesses a remarkable ability to regenerate quickly, meaning the duration of welder’s flash is generally short. For typical, uncomplicated cases, acute symptoms usually resolve completely within 24 to 48 hours from their onset. This rapid healing occurs as healthy surrounding cells migrate to cover the damaged area, effectively resurfacing the cornea.
The severity of the initial flash burn, determined by the intensity and length of UV exposure, is the main factor influencing recovery speed. A brief flash may result in symptoms lasting only a day, while prolonged exposure may require the full two-day recovery period. Persistent discomfort or blurred vision extending beyond 48 hours can indicate a more severe injury or potential complication. Isolated incidents of welder’s flash rarely result in permanent vision loss or lasting damage.
Home Care and When to Seek Medical Help
Home care focuses on managing intense pain and discomfort while the corneal cells heal. Applying a cold, damp compress over the closed eyes can help soothe the burning sensation and reduce inflammation. Resting the eyes in a dark room is also recommended to minimize the painful effects of light sensitivity.
Over-the-counter pain relievers, such as ibuprofen or acetaminophen, can reduce the ache and sharp pain. Individuals must resist the urge to rub their eyes, as this worsens damage to the compromised corneal surface. While the condition usually resolves on its own, medical attention should be sought if the pain worsens after 24 hours or if symptoms persist beyond 48 hours. A doctor’s visit is also necessary if there is a noticeable decrease in vision or if signs of infection develop, such as thick discharge or increasing redness.
Essential Prevention Measures
Preventing welder’s flash relies entirely on using the correct protective gear every time an arc is struck. The most important equipment is a welding helmet equipped with a filter lens of the appropriate shade number. For most arc welding processes, this filter should be between Shade 10 and Shade 14, depending on the amperage, with higher numbers offering greater protection for brighter arcs.
Ensure the helmet is in the correct down position before initiating the arc to prevent momentary exposure. Wearing safety glasses or goggles with side shields underneath the welding helmet provides an additional layer of protection against flying debris and stray light. Welding areas should also be shielded with non-reflective screens or curtains to contain the intense UV radiation and protect others nearby.