Pterygium and Pinguecula
Pterygium is fleshy tissue that grows over the cornea (the clear front window of the eye). It may remain small or may grow large enough to interfere with vision. A pterygium most commonly occurs on the inner corner of the eye, but can appear on the outer corner as well. The exact cause is not well understood. Pterygium occurs more often in people who spend a great deal of time outdoors, especially in sunny climates. Long-term exposure to sunlight, especially ultraviolet (UV) rays, and chronic eye irritation from dry, dusty, smoky conditions seem to play an important causal role. A dry eye may contribute to pterygium.