Pterygium in welders.

Pterygium is thought to be hyperaemia of fibrovascular tissue on to the cornea caused by ultraviolet radiation of sunlight. We observed a significantly high incidence of pterygia in welders who were exposed occupationally to excess ultraviolet radiation and found a close relationship between the incidence and the length of employment as a welder (r = 0.975, p less than 0.05). This study attempts to clarify the causative relationship between ultraviolet radiation and pterygia.