A Non-reversing mirror is a mirror that presents its subject as it would be seen from the mirror. It is possible to make a non-reversing mirror by connecting two regular mirrors at their edges at a 90 degree angle. If you position the join so that it is vertical and look into the angle, you will see a non-reversed image of yourself. You sometimes see this in public toilets where there are mirrors on two walls which are at right angles. Looking towards the corner, you can see such an image. The problem with this type of non-reversing mirror is that there is a big line down the middle interrupting your view. However, if first surface mirrors are used, as well as the angle set to exactly 90.00 degrees, the join can be made invisible.
Another type of non-reversing mirror can be made by making the mirror concave (curved inwards like a bowl). At a certain distance from the mirror a non-reversed image will appear. The disadvantage of this is that it only works at a certain distance.
A patent for a non-reversing mirror was issued to John Joseph Hooker in 1887.