Pterygium

A pterygium is a noncancerous growth that starts in the clear, thin tissue over the eye (conjunctiva). This fleshy growth covers the white part of the eye (sclera) and grows onto the clear protective layer on the front part of the eye (cornea). One or both eyes may be affected. A pterygium may have no symptoms, or it may cause eye irritation, itching, and redness. If the growth is large, it can cause vision problems. Most of the time a pterygium is harmless, and no treatment is needed. If vision is affected, it should be removed.

It's not known exactly what causes a pterygium. Exposure of the eyes to the sun (UV-light exposure), dust, wind, and low humidity are thought to be factors. People who spend a lot of time in the sun, or who live in places where the sun’s rays are intense, may have an increased risk of developing pterygia. To protect your eyes, wear sunglasses with side shields that block 100% of UV rays when outside. This may help prevent the condition from coming back or getting worse. It is also helpful to wear a wide-brimmed hat when outside.