Pronounced “ter-idg-ee-um”, a pterygium is a wedge-shaped growth of thickened tissue that covers the white part of the eye. It usually starts growing near the inside corner of the eye, and can extend onto the cornea towards the pupil. A pterygium can affect eyesight and cause other annoying symptoms. In these cases, it can be surgically removed. Pterygiums are not cancerous. Their growth is usually very slow and surgery is not always required.