Marc Jacobs MMJ 115 Sunglasses
I'm on my second pair of ESS Flyby's now (my last set mysteriously disappeared after four years of loyal, eye protecting Army service). Not much to say - they're great sunglasses. I like the style; the matte finish is nicely tactical and the smoked lenses look pretty cool, and they do a good job keeping debris out of your eyes. I've been working around a belt sander, a table saw, and various other woodcutting tools recently, and these babies have kept me nice and ocular-ly safe. My last pair withstood a lot of abuse - getting dragged up into mountainous training areas, through extreme heat and cold, and general rough handling with nary a problem. If there's a negative, they do fog up if you're sweating and keep them pressed flush to your face. Moving them forward about half an inch solves that problem, though, and I'm not sure that I've had any sunglasses, ever, that didn't have the exact same issue.
If you're on the fence, get'em. They're worth it. As a nice little bonus, they come with a drawstring pouch/cleaning cloth and a semi-rigid zipper case for extra protection.