Harkening back to TOS, most people probably don't know that it was actor Sean Kenney who played the wheelchair bound Captain Pike in "The Menagerie". Later, he was to appear in "Arena" as navigator Lt. DePaul. If Pike hadn't suffered any facial damage from the bertol rays, he might have looked like this:
An FYI, I met Sean Kenney at a convention a few years ago. Very nice man. Anyway, he had a beard, longer hair, and was, of course, much older. Well, he had a picture of Jeffrey Hunter from a movie he had done (I think it was King of Kings.) Hunter looked then, with the makeup from that film, a LOT like Kenney does today. Their choice of recasting for The Menagerie really was right on the target.