This design for a pair of foldable glasses may look a little bulky, but it more than makes up for that in convenience. After you take off the glasses, the lenses fold neatly into the sides, which contract to form a hard case that you can place into your pocket. No more putting your glasses into your shirt pocket only to have them get smashed when some jerkface bumps into you on the street.
These glasses are called "Optigami", combining "optical" and "origami". Since this is just a design, there's no telling whether it'll get turned into an actual product or not. But enterprising DIY'ers could try making their own out of duct tape and chicken wire.