A pterygium (pronounced ter-idge-ee-um) is a triangular-shaped band of degenerative tissue that grows from the white of the eye onto the clear window at the front of the eye, the cornea.

It results from eye surface damage due to exposure to ultra-violet light, wind, glare or dust.

Pterygiums increase susceptibility to dry eyes or inflammatory anterior eye disease. Treatment may start with eye drops and, in some cases, surgical removal. Wrap around sunglasses and protective eye wear can help prevent these growths.