Mirrored Hockey Visors In The NHL: Should They Be Allowed?

Ok, I've done a post on hockey cages and shields, but not on certain types of shields.  Visors have become very popular in the sport and in the NHL over the past 10 years or so.  Now, I don't have time to study every player in the NHL, but I don't think anyone currently wears a mirrored visor.  The last person I know of that wore one was Ovechkin and I think he just uses a tinted visor now.  I