Very poor design
I purchased 3 pairs of these.  The first pair was broken on arrival.  The second pair broke within a week (the mechanism that clips them to your glasses and allows you to flip the lens portion up).  At best the lenses would swing back and forth freely in front of your eyes and couldn't be kept flat against your actual glasses.  Then the clip let go entirely and they couldn't even be clipped to your glasses.  The exact same issue as the first pair that arrived broken.  The third pair is holding on at the moment, but you can tell the mechanism is poorly designed and will be broken soon with exactly the same problem.  The short time I've been able to use them they worked ok, but clearly I can't recommend purchasing these.  Three pairs and I'm down to my last one in about two weeks.
Rating: 1 stars