On a recent episode of High Stakes Poker, durrrr, Eli Elezra, and Daniel Negreanu discuss whether or not players should be allowed to wear sunglasses at the poker table, mostly coming to the conclusion that no, it shouldn’t be allowed.
Their main reason is that it could enable cheating, as a player could theoretically mark certain cards with a substance only visible with the right sunglasses. While that sounds decidedly James Bondish it has actually happened at casinos in the past.
We’re not a big fan of sunglasses at the table ourself, but more because we’d rather not have to look at Greg Raymer and his stupid glasses anymore:

OMG so scary! You intimidates me! I folds and cash out immediately!
I mean, come on Mr. Raymer. You’re a smart dude and a good poker player. Get rid of the corny glasses.
This guy, however, you can keep the glasses on, as the look really works for you:
