Up until a month ago, i would have thought they were stupid, but with a freak mtn biking accident with fracturing c4 thru c7 and having the whole section anteriorly plated, i am now wondering which are the best model out there, !( since there are a couple models now)
Belay glasses can really save you a lot of pain after you've been climbing for a few hours. They are a bit pricy though... these guys http://www.belayshades.com seem to be the best deal out there at the moment. About $100 less than CU if you can believe that.