Pterygium is an abnormal growth of fibrovascular tissue on the conjunctiva of the eye. It usually appears on the side near the nose but can affect both sides of the eye.
Causes:
Prolonged exposure to sunlight is the main factor in the development of pterygium. However, other factors such as exposure to dust, dirt, heat, wind, dryness, and smoke can also worsen an existing pterygium.
Exposure of the eyes to industrial solvents and chemicals may also cause pterygium.