Not all the white in my eye is yellow just round the outside what is this?

Pinguecula: Pinguecula is benign degeneration of the conjunctiva usually occurring adjacent to the cornea nasally and related to exposure to uv radiation from the sun. It appears a a yellowish elevated area . Treatment is not necessary except for cosmesis or if it becomes chronically irritated unresponsive to lubrication or topical anti inflammatory drops. Surgical excision is relatively easy to perform.

Pinguecula: Sounds like a pinguecula, which is a deposit/build up on the white part of the eye (sclera) due to uv light and dryness of the eyes. You can use artificial tears, and use a cap and/or sunglasses when outdoors.