If you look in a mirror you seem to see yourself reversed left-to-right. Your left eye appears to be your right eye in the mirror. Yet the vertical direction is not reversed.Your chin is still at the bottom of your face. What happens if you look at a mirror while lying down? Now left and right are not reversed—your chin is on the same side of both you and your image. But if your right eye was higher than your left, then in the image the left eye will be higher. What indeed is reversed?

What makes a glove right-handed or left handed? If you examine a vinyl or latex glove you’ll notice that it can fit on either hand. How does such a glove differ from an ordinary glove? The thumb is in line with the fingers. In other words, there is no front or back! A mirror reverses not left and right or up and down, but front and back. When you look at yourself you are facing the opposite direction. It’s just like facing another person—his or her left and right sides are also reversed.