Where I do agree more customizing options like this are awesome ideas, but I feel if eventually they were to add all of these ideas I see on the forums, it would defeat the purpose of a preset in a way.
This would be pretty neat. I think a lot of people who have characters that are blind only in one eye would benefit from this addition a lot. Of course there would be more interesting variation/customisation, but this was the first thing that came to mind.