Well, I'm just going to try and ease your mind here. I have a female girl, she is our oldest that I can tell, and her eyes are clearly bigger than most of our other snakes. Much like your photo's. She has been to a vet, not for her eyes, but he is very experienced with snakes and has kept them for decades. He never mentioned a thing about her eyes looking off, so I never put another thought into it.
Also, I have one male that seems to have the same sort of size in comparison, however they both act normal and have never acted in any way to suggest that they were in discomfort.
If they try to prescribe you any more medication, think about getting a second opinion as well with another snakes Vet.