I made a glasses case for my reading glasses, a while back.  It was beautiful, made out of translucent green PLA.  Only problem was that it was just a little bit too small, and ended up breaking the glasses! I redesigned it, in a custom shape, to conform to the glasses, and printed it with thinner walls.  It, too, is beautiful, but now more functional. Upper left is the old case, with broken glasses; new one is on the lower right.  Note the unusual profile in the new cap, and the thinner walls.