A pterygium is a non-cancerous growth of tissue on the conjunctiva, the thin membrane that covers the white part of the eye. This triangular or wedge-shaped growth may extend onto the cornea, the clear front surface of the eye, and is often associated with prolonged exposure to ultraviolet (UV) light, wind, dust, or dry conditions. Pterygia are more common in individuals who spend significant time outdoors, particularly in sunny or windy environments. While many pterygia remain small and asymptomatic, larger or inflamed growths can cause redness, irritation, and a foreign body sensation in the eye.