I started wearing Smith Optics Lochsa bifocals this year and like them very much. Bought 2 pair from Madison River Fishing Co. ( 1 pair w/copper lens & 1 pair w/brown lens ) at half off regular price. MRFC has Smith Optics "Lost River" bifocals on sale now for half off. A high quality product and a very nice company to do business with. Also bought a pair of Cloudveil Crystal Creek wading pants from MRFC at about half off.
I buy the $20 polarized ones from ****'s and places like that. They work fine. I'm not saying nice pairs aren't better, I'm sure they are. But I'm good for losing or breaking a pair every 2 years or so, and investing big money just isn't worth it.
I use the cheapo glasses from Walmart (Berkley brand). I've gone through a few pairs and they work pretty well. My buddy Greg got some prescription polarized glasses and was seeing fish better than I was not too long ago and he's pretty blind without his glasses, so like anything the more you spend the more you'll probably get out of a product. One day when I'm making 6 figures I can splurge on a nice pair of polarized glasses.
I like Oakley as well and search ebay when I need a new pair. I'll secong the Sierra Trading Post suggestion. They have a good selection. I prefer amber polarized lenses for an all purpose use.