Yes, welding light is harmful to welders’ faces, especially for eyes. Extreme heat is generated when the arc of the weld is created. This high heat or energy can be proven destructive for the user. Some users do not wear any helmets or any protective gear. For that person, welding light can cause severe damage.
In some cases, welding light can cause blindness or permanent loss of eyesight. However, it is sure that it can weaken the eyesight to either a small or large extent. The UV/IR radiations of the light have to swear kind of the effects on the eyes.