These are really cool, and super fun to use! Manufactured by Swift Instuments, Boston c.1950s-60s, these glasses, with prisms for the lenses, were made for reading or watching television while lying down--so as not to have to either crane one's neck to see, to to hold your book up in front of you. What they also allow you to do, when standing up, is to see what is going on behind you!
In their original case and box, with printed booklet which makes for pretty fun reading about "this new seeing pleasure for your relaxing hours..."! Box measures 6 3/4" x 2 3/4" x 1 5/8". Very good condition. Perhaps there is some loss of padding that once existed on the bridge.