A polyp on the eye is called a pterygium. A pterygium is very small and does not have irritating symptoms such as redness or grinding. If the pterygium grows into the cornea or even into the pupil area, it can cause astigmatism and affect vision, as well as cause repeated congestion, grinding, tearing, and photophobia. Pterygium excision plus autologous corneal limbal stem cell transplantation is a common surgical procedure to avoid recurrence of pterygium after surgery. Pterygium often grows on the nasal side, but can also grow on the temporal side. It can grow in one eye or both eyes at the same time, and the growth of pterygium is associated with long-term sand and UV irritation.