A pterygium (teh-RIJ-ee-um) is an elevated, wedged-shaped growth of the scleral conjunctiva that invades the cornea. Pterygia are benign (non-cancerous) growths, but contain blood vessels and form scar tissue on the eye.

Because a pterygium resembles tissue or film growing over the eye, a person who has one may become concerned about personal appearance.

As with pingueculae, prolonged exposure to ultraviolet light from the sun may play a role in the formation of pterygia.