Pterygium

A pterygium is a benign growth of the conjunctiva. It tends to grow from the nasal side of the sclera. It is caused principally damage from sun exposure and the reason it appears on the nasal side is that the cornea acts as a lens for sunlight on the medial/nasal side but not on the lateral/temporal side because of the shadow cast by the nose.

As it is a benign growth, it requires no treatment unless it grows to such an extent that it covers the pupil, obstructing vision. Wearing protective sunglasses (with side shields) will prevent their formation or stop further growth.

Occasionally found as an incidental finding in middle aged patients who spend a lot of time in the sun.

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