How Do 3D Movies Work?

Dr. Rachel Smith
by Dr. Rachel Smith

Is there anything better on a hot summer day than finding refuge at the movie theater? Summertime is when all of the big blockbusters come out to entertain us and keep us enthralled in air-conditioned comfort. However, very rarely do they make summer blockbusters anymore without the important box office component: 3D technology.

thumbnail-3But what exactly is 3D and how does it work?

Your brain and eyes work together in order to perceive things in three dimensions. Binocular vision or stereoscopy is how each eye observes the same object from a slightly different perspective. Each of those images is sent to your brain, and your brain gives the image depth, or 3D.

The way the movie is shown in combination with specific eyewear is what actually causes your brain to interpret what you are seeing in 3D. What is being presented on the screen are slightly different orientations of the same image. Your eyes just see one complete image because the lenses of your glasses allow a different image to each eye, and your brain puts it all together.

In old versions of 3D movies (all those monster movies from the 50s), images were captured with one version being blue and the other red. The cardboard glasses of the day featuring one red and one blue lens would filter out the same colored image letting each eye see a separate version of the image. Your brain would then put those two images together for the 3D. The problem with the old version of 3D was that it was impossible to do a color movie this way because the way the glasses would filter would be through color.

In newer 3D movies, polarized lenses in those cool Ray Ban-looking glasses you receive at the theater help each eye view the different orientation separately. Your eyes just see one complete image, because the polarized lenses of your glasses present a different image to each eye with your brain putting it all together.

There are some people who are unable to see movies in 3D. Conditions such as amblyopia or strabismus cause the eyes to perceive information differently enough that they are unable to feed the correct information to the brain for it to process the image in its intended three dimensions. People may not even realize that they suffer from a condition such as these because they have learned other visual cues to help them with depth perception. Our brains can fake us out of true binocular vision.

If you have problems viewing 3D movies or experience headaches or nausea while doing so, you may have an issue with your binocular vision. One of our optometrists would be able to refer you to our Center for Vision Development. They could recommend a treatment of Vision Therapy to start you on a path of your eyes and brain working together in order to enjoy the world around you as intended.

So save us a seat and enjoy the show!

Save Your Data