Pterygium (pronounced tur-IJ-ee-um) and pinguecula (pronounced pin- GWEK-yoo-la) are growths on the cornea (the clear front window of the eye) and the conjunctiva — the thin, filmy membrane that covers the white part of your eye (sclera). Both growths are noncancerous and are fairly common.
A pinguecula (above) is a yellowish patch or bump on the conjunctiva, near the cornea. It most often appears on the side of the eye closest to the nose. It is a change in the normal tissue that results in a deposit of protein, fat and/or calcium. It is similar to a callus on the skin.
A pterygium (also known as surfer's eye or farmer's eye) is a triangular-shaped growth of fleshy tissue on the white of the eye that eventually extends over the cornea. This growth may remain small or grow large enough to interfere with vision. A pterygium can often develop from a pinguecula.
Some pterygia may become red and swollen on occasion, and some may become large or thick, making you feel like you have something in your eye. If a pterygium is large enough, it can actually affect the shape of the cornea’s surface, leading to astigmatism.
It is not entirely clear what causes pterygia and pingueculae to develop. Ultraviolet (UV) light from the sun is believed to be a factor in the development of these growths. Other factors believed to cause pterygia and pingueculae are dry eye and environmental elements such as wind and dust.