A pterygium is a fleshy growth that invades/grows into the cornea (the clear front window of the eye). A pterygium may be small or grow large enough to interfere with vision and commonly occurs on the inner corner of the eye.
The exact cause is not well understood. A pterygium occurs more often in people who spend a great deal of time outdoors, especially in sunny climates. Long-term exposure to sunlight, especially ultraviolet (UV) rays, and chronic eye irritation from dry, dusty conditions seem to play an important causal role.
When a pterygium becomes red and irritated, topical eyedrops or ointments may be used to help reduce the inflammation. If the pterygium is large enough to threaten sight, is growing or is unsightly, it can be removed surgically.
Despite proper surgical removal, the pterygium may return, particularly in young people. Surface radiation or medications are sometimes used to help prevent recurrences. Protecting the eyes from excessive ultraviolet light with proper sunglasses and avoiding dry, dusty conditions may also help.