The conjunctiva lines the inside of the lids and covers the sclera (white part of eye). The cornea lies in front of the colored part of the eye (iris). A pterygium is a slightly elevated, superficial, wing-shaped, fleshy conjunctival growth that covers and alters the shape of the cornea. It may be yellow, gray, white, pink, red, or even colorless. It may have blood vessels. Pterygium may be small or grow large enough to interfere with vision. Most patients with pterygium express concern regarding the appearance of the lesion, or because the lesion is irritating the eye or it is adversely affecting vision. Typically, the pterygium is first noticed on the conjunctiva, and then is noted to gradually grow onto the cornea of the eye. When the growth is confined to the conjunctiva, it is known as a pingueculum. When it extends onto the cornea it is called a pterygium. Left alone, some pterygia will eventually grow to obscure the optical center of the cornea, thereby obstructing vision. Facts about Pterygium

• A pingueculum may develop into a pterygium.
• Commonly found in individuals who spend a lot of time in the sun or live in dry, windy, smoky, dusty, sandy tropical climates.
• Reported to occur in males twice as frequently as in females.
• Almost always confined to the exposed surface of the conjunctiva, and usually on the side closest to the nose. Less often, it can also occur on the outer side of the cornea.
• One or both eyes may be involved.
• Some pterygia grow slowly throughout a person's life, while others stop growing after a certain point.
• Pterygium is alteration of normal tissue resulting in a deposit of protein and fat.
• Usually a pterygium does not lead to anything catastrophic such as a serious loss of vision or blindness.
• Can eventually distort vision due to growth onto the cornea, and eventually even onto the central part of the eye blocking light from entering.
• Removing a pterygium surgically typically resolves the problem.