Every person at some point has to come to terms with that it’s not acceptable to check out the opposite sex while in mixed company. It’s just not the best manners to spin your head around quickly to check someone out. So for those that just can’t help craning their neck around on occasion, there are these Spy Glasses. The dark mirrored lenses work like a rear view mirror. They give view of what’s going on both sides behind you. You can pick them up for $14.97 on Things You Never Knew Existed.