Oakleys obviously aren’t a cheaper option, but they’re great to wear and if the threads n here are to be believed their CS is very good at repairing/ replacing broken glasses for cost.
I’ve always used cheaper glasses before, but after getting my first pair of Oakley’s 18 months ago I’ve not looked back- currently have three pairs for different uses! Vented Jawbones with VR28 lenses for daytime use, and Flak Jacket’s with a clear lens for night-riding.
A good tip for getting the Flak-Jackets at a good price is getting the the Standard Issue (SI) ones which are all black, the prices have risen since last year, but I should imagine they’re still much better value than the normal ones.