What is the primary cause of "Arc-eye" in welding?

The primary cause of "Arc-eye," also known as photokeratitis, in welding is ultraviolet (UV) radiation. When a welder initiates an electric arc, the intense light produced emits a significant amount of UV rays. These rays can penetrate the cornea of the eye, leading to inflammation and painful symptoms commonly associated with Arc-eye, such as redness, tearing, and a gritty sensation in the eyes.

While exposure to loud noises, electromagnetic fields, and chemical fumes can also pose risks in a welding environment, they are not responsible for the specific issue of Arc-eye. Instead, it is the UV radiation from the welding arc that directly affects the eyes, making it crucial for welders to wear proper protective eyewear that can filter out harmful UV rays to prevent this condition.