Re: Best fly fishing glasses?
I have a pair of Smith glass sunglasses that are what I would characterize as light brown/amber (they're darker than some yellow-brown Orvis glasses I have, but lighter than some darker brown Hobies I also have). Frankly, I like them better than the others I have (including some super-expensive Bolla's I had to purchase on a trip when I forgot my sunglasses at home), mainly because they're glass and don't seem to pick up dirt as quickly as the others which are all plastic. However, like several have already said, I wear sunglasses as much for eye protection as for sun protection, fish spotting, etc., and not being sure if they are impact-resistant, usually end up using the Hobies or Bolla's, both of which have additional interchangeable lenses - useful when on the water and light conditions change.
Flyflinger, you didn't mention whether your Costa's were polarized or not. If the latter, that would be an easy explanation for why you're having trouble seeing through the glare when trying to spot fish. But I have found out the hard way that spotting fish, even with the best polarized sunglasses in the business, is an acquired skill as Frank and Rip Tide said.
On the whole, I'd rather be in Wyoming . . .