The toy collection contains a range of unusual glasses, and Tim 'models' a few of them here.
Some are merely playful, and designed to amuse the onlookers, such as the glasses that contain two spooky staring eyes - in fact these eyes are holographic images!
There are glasses that show you what is happening behind you, and simultaneously conceal your eyes, so that people standing in front of you are not aware that you are looking in your 'rear view mirror'.
The glasses with 90 degree prisms are interesting. As Tim says, these are 'almost useful'. If you stood up normally, these would just show you your feet. The idea is that you can lie flat on your back, and watch a television placed at the foot of the bed. Alternatively you could lie flat on the beach, yet simultaneously keep an eye on any small children in the party, who are playing in the water.