I know someone with yellow where the white of your eyes are and a white halo right above the pupil. what could that be?

Jaundice!: When there is a high level of blood bilirubin, then the sclera changes color to a yellow tone ( jaundice). The cornea which is a clear dome in front of the colored part of the (iris) acts as a sponge & picks up material such as cholesterol over the years and develops a whitish ring called "arcus sinilius" which is also benign. In a young person it may be sign of very high cholesterol. Get checke.

Yellow: The yellow area is probably a pingueculum, an area of collagen breakdown due to the sun or wind. The white area is arcus senilis, due to cholesterol deposition in the cornea.