Pterygium (pronounced ter ig ee um) Pterygium is a raised, wedge-shaped growth of the conjunctiva. It is most common among those who live in tropical climates or spend a lot of time in the sun. Symptoms may include irritation, redness, and tearing.   Pterygiums are nourished by tiny capillaries that supply blood to the tissue. For some, the growth remains dormant; however, in other cases it grows over the central cornea and affects the vision. As the pterygium develops, it may alter the shape of the cornea, causing astigmatism. If the pterygium invades the central cornea, it is removed surgically. Since pterygiums are most commonly caused by sun exposure, protecting the eyes from sun, dust and wind is recommended. Instilling artificial tears liberally is also helpful to decrease irritation. In some cases, steroid drops are prescribed to reduce inflammation.