I ordered a pair of these as a Christmas gift for my oldest. He needs glasses for xc skiing. They arrived yesterday. They feel very flimsy. I hope they don't shatter into eyes and blind him for life... :\
These are apparently UV resistant among other things. I've found the lenses to be very good for most things, and ventilation adequate for road and mountain use.
At 1/10th the cost of other sunglasses, you can buy an extra set if they do get scratched. I don't know about impact resistance, but if the lenses are polycarbonate they should offer some resistance.