Pretty self-explanatory... lol.
I assume my screenshots will be enough, as you can't really portray it in any other way? If they aren't good enough, please tell me how I can take a screenshot of this. Because, y'know, it could be kinda hard to do.
Please note that this also makes the Pyro's glasses invisible. Afaik there is no way to make JUST the Pyro glasses visible.