I'm jumping in on this one late, and I've more or less skimmed what everyone's said.
If your assignor says, "no sunglasses," then no sunglasses. It's stupid, but hey, they hold all the cards. Our org says PU in ASA SP has ALL calls at 3rd and home. I think it's stupid, but that's their call. Let's not debate that one, though.
If you have a discussion with a coach, I agree that glasses should come off, even if it's 115 degrees under the bright afternoon sun. I personally like to stand side-by-side with a coach when I'm talking with him/her, so I think that it's perfectly reasonable to say, "hey, coach, let's turn this way so we're not facing the sun." You're showing the coach that you're accommodating and not adversarial. At that point, now you've got the coach where you want him. If he wants to turn towards you and get in a shouting match, he'll have to do so with the sun in HIS eyes, not yours. This may deter him from doing so, but if he does, he may not last long before giving up. How long does a coach really want to argue when he's being blinded?
If I discuss things with a coach, I take my sunglasses off, even if I have the clear lenses in.
And let's tone it down, guys. We're starting to act like the coaches we're discussing.
