contact lenses for different sized irises

One of my irises is larger than the other. I am interested in contacts that could correct this cosmetically. I am thinking of a lens with a ring around the edge that would expand the colored part of my iris (brown). I'd want it clear in the center because I think colored contacts would look unnatural. Would it be possible to order these lenses custom somehow? I'd probably have to get checked out to make sure the size is exact. What costs would be involved?

thanks.