A pterygium is an abnormal, non-cancerous growth of the conjunctiva. The conjunctiva is the thin mucous membrane that covers the white part of the eye and lines the inside of the eyelids. A pterygium appears as an elevated triangular whitish thickening that that is caused by excessive growth of the conjunctiva and extends on to the surface of the eye. If it grows large enough, it can interfere with vision and cause redness, irritation, and tearing. While the exact cause is not fully known, a pterygium is thought to be caused by exposure to UV rays. It is often irritated in dry dusty conditions and therefore is found more in people who have outdoor occupations. A dry eye condition may also contribute to this thickening.

Excision Surgery may become necessary if drops or ointments are unable to relieve the condition or if the pterygium grows large enough to blur vision. When the pterygium is surgically removed, an autograph is needed to fill in the area where it was removed. The graph is painlessly taken from the underneath portion of the upper eyelid and is attached by using a transparent glue made from clotting proteins. Using a self-transplant also helps in preventing the reoccurrence of pyerygium.

Most patients can return to normal activities after 1 or 2 days following the surgery.