Well, I can see that you would like to get a pair of sunglasses that could give you both protection and visual aids. So, as you can see, Bloomingdale's is one of the most famous department store in America, and you could of course see loads and loads of designer sunglasses with prescription, but, most of them are just regular ones, however,sometimes they could be very expensive, so you'd better bring more money.
There are many places like online stores offering the prescription sunglasses which could be suitable for those with prescription who need to go outside in the strong lights. The online stores conclude the walmart, amazon and so on. You could go to their online store to have a search. There must be the one that you like.