The intense, blinding flash produced by arc welding can lead to a severely painful eye condition commonly known as “welder’s flash,” “arc eye,” or “flash burn.” This discomfort is a genuine physical injury to the surface of the eye, similar to a sunburn on the skin. The pain is a direct consequence of the powerful light energy generated during the welding process, which damages the delicate outer layer of the eye. Understanding the specific type of energy involved helps explain why this exposure causes such a delayed and intense reaction.
The Invisible Danger: Ultraviolet Radiation
The primary harmful agent from a welding arc is not the bright visible light, but an invisible form of energy called Ultraviolet (UV) radiation. A welding arc produces a broad spectrum of radiation, including high levels of UV-B and UV-C light, which are the most energetic and damaging wavelengths. These high-energy photons are potent enough to cause rapid cellular damage even with a brief exposure. The intensity of this UV radiation is significantly higher than natural sunlight, which is why exposure to an arc can cause injury much faster than being out in the sun.
Understanding Photokeratitis
The medical term for a welding flash injury is photokeratitis, which describes the acute inflammation of the cornea. The cornea is the clear, dome-shaped outer layer at the front of the eye, and its outermost layer is the epithelium. This epithelial layer is where the intense UV radiation is primarily absorbed, protecting the deeper structures of the eye. The energy absorbed by the epithelial cells causes them to die and detach from the underlying tissue. This cellular death and sloughing off exposes the dense network of nerve endings located just beneath the epithelium. The resulting irritation of these exposed nerve fibers is the source of the characteristic, severe pain.
The Delayed Pain
The long delay between the exposure and the onset of pain is characteristic of photokeratitis. Symptoms typically do not begin immediately but appear 6 to 12 hours after the initial flash exposure. This timeline occurs because it takes several hours for the UV-damaged corneal epithelial cells to fully break down and slough off. Once the underlying, highly sensitive nerve endings are exposed, the pain begins, often waking a person up in the middle of the night. The resulting pain is often described as an intense, gritty sensation, like having sand stuck in the eye. Other common symptoms include severe tearing, involuntary spasms of the eyelid (blepharospasm), and extreme sensitivity to light, known as photophobia.
Immediate Steps for Relief and Recovery
If you suspect you have photokeratitis, immediate self-care can help manage the intense discomfort while the eye heals itself.
Self-Care Steps
- Remove any contact lenses and avoid rubbing the eyes, which can worsen the damage to the corneal surface.
- Staying in a dark room or wearing sunglasses will help reduce the pain caused by light sensitivity.
- Applying a cold, damp washcloth or compress to the closed eyelids can help soothe the inflammation and provide temporary relief.
- Over-the-counter artificial tears may also be used to lubricate the eye surface and ease the gritty sensation.
The corneal epithelium has a remarkable ability to regenerate, and the condition usually resolves completely within 24 to 48 hours without lasting damage. Medical attention is necessary if the pain is unrelenting, symptoms persist beyond 48 hours, or if there is any noticeable change or loss of vision.