How Do Bed Prism Glasses Work?

You’re likely reading this because you’ve seen the 2007 hit THE BUCKET LIST, or heard from someone who has about the glasses Jack Nicholson’s character wore in the movie. Perhaps a doctor, nurse, or rehab specialist has recommended them to you so that you can more easily read or watch TV while lying flat in bed. They’re prism glasses, and they allow you to adjust your angle of vision 90 degrees.

But how do they work?

All About Bed Prism Glasses

Many assume they simply incorporate mirrors to reflect back an image. Technically, they do use mirrors, but standard mirrors are unable to reproduce an identical image. As you know, mirrors produce a reverse image. Say, for example, you stand in front of a painting on a wall. If you hold a hand mirror above your head, look up, and adjust the mirror so it shows the wall in front of your body, you’ll see the painting…but it will upside down.

A periscope overcomes this by using two mirrors – reflecting one mirror’s inverted image off the other mirror, thus inverting it again so that it appears to be right-side up. But a periscope is not designed to change the angle one views a reflected image; just extend the length of a reflected image. When a periscope is used in a submarine, the viewer has a direct line of vision to an image happening many feet above their head, but the viewing angle has not changed. They look directly into the viewer and see the image of what’s directly ahead on the surface of the water. So the technology used to create a periscope does not apply to adjusting your vision angle 90 degrees.

Only a mirror can do that.

Obviously, no one wants to view an upside-down television image or try to read an upside-down book. So to compensate for the inverted image, prism bed glasses utilize prism mirrors and the science of refraction to simultaneously reflect and invert an image.

A prism works by bending light; a mirror reflects it. When combined they reproduce an image identical to the one projected at a different angle. Bed prism glasses combine the technologies to reflect and bend an image so that it appears to be directly in front of your eyes.

Visit Rx-Safety to purchase a pair of bed prism glasses. Two different styles are available: Prism Glasses for those with 20/20 vision, or Fitover Prism Glasses, which are designed to be worn over prescription eyeglasses. Now you can enjoy the benefits of prism bed glasses regardless of your vision requirements.