It's on the white of your eye? It could be one of two things (search for the words pingueculum and pterygium for pics and info). I copied a description:
A pingueculum is a small bump on the white of your eye, usually on the side closest to your nose. The bump may be clear or yellowish. A pterygium is a small bump that has tiny blood vessels in it. This growth can get bigger and cover part of your cornea, which is the clear outer layer on the front of your eye.
These are almost always benign inclusion or sebaceous (oil) cysts. They are common in that area. Most just leave alone.