My son says that one of the lenses popped out the first time he wore them.  He threw all the boxes and tags away, or I'd have him return them.  He says he'll still wear them, but if someone "smacks" him on the back/side of the head (which 20-year-old boys tend to do), it'll likely pop out again, and  perhaps be lost or scratched.

I'd rather pay more for quality.