Originally Posted by The Ones
Big question, if scott was vaporised, why didnt his glasses blow? Look how quickly they went in the infirmary
Basically because they weren't in Scott's hands. Jean was holding them or let them go. So whatever happened to Scott didn't happen to the glasses.
Also, they were meant to be used as a plot device. Remember, no one knew that Scott went to Alkali Lake. It was sort of an obvious way to tell the chars and the rest of the audience "Scott was here".
If it wasn't for the glasses, there would probably be no one for anyone to know that Scott had in fact been there. They certainly didn't find his motorcycle.