The only problems I've had is with them fogging up while wearing a headnet and when using binos.Iprefernot to be wearing glasses when using binos even with thetwist downeye cups. My vision isn't that bad, so I just don't wear them while hunting. In fact, my regular glasses got scratched last september when I moved and pretty much don't wearthem at all anymore. I never bothered replacing them. I wear prescription shades tho.