I can see why the idea wouldn’t work. Minor characters with disabilities, unless they were to gain more major roles, wouldn’t really have any reason to have them. I remember reading the post Apotheosis by @DarkMaestro where the character Helryx has a prosthetic (or peg leg) which makes her look more interesting and adds to her history.
I think receiving a scar like that (to the point where one eye is a different color to the other) would impair his vision (seen here), as well as warrant for a mask built to aid him.