If you have sensitive eyes or 20/20 vision (or better) I wouldn't recommend these. Had a pair, they had slight magnification which caused me a really bad headache for 2 days after using them for a few hours. Never used them since, this was a 4 years ago or so.
AbaseesAgreed, these could aggravate your eyes if they are sensitive to changes in magnification.
Just to offer another perspective on 20/20 vision, however, I have better than 20/20 vision and have comfortably enjoyed wearing Gunnars on and off for over 3 years now. Well, comfortably except for the slightly narrow 120 mm temples on my model, the RPG. Thankfully, virtually all of their current models feature wider temples than that (and the RPG has been discontinued), so I'm joining this drop to hopefully get a pair with a better fit for my head.