If you are bed-ridden due to medical reasons, hospital stay, re-hab etc., but wish to read, watch TV or see what's past the end of your bed these prism glasses can be a Godsend.

Basically they allow you to see what's at your feet while looking straight ahead. So if you are lying down (supine) you are looking at the ceiling, but actually seeing what's in the direction of the end of the bed.

Also for general purpose, these prism glasses provide a very comfy way to read your favourite book while keeping a nice relaxed neck and head position.