A pterygium (plural pterygia) is a wedge-shaped growth of abnormal tissue found on the white of the eye between the eyelids.
Ninety per cent of pterygium are found at the corner closer to the nose. Pterygia are benign (non-cancerous) growths that may enlarge to extend onto the cornea.
Pterygia may occur in one or both eyes and at different rates of growth. They tend to be progressive and grow across the cornea and this tends to be associated with more symptoms and visual disturbance. Sometimes they may stop growing, become quiescent, and remain this way.