Providing the ultimate immersive experience, 3D glasses allow viewers to become part of the action and see images as if they were jumping right off the screen. Although they may seem like a relatively new invention, 3D glasses and 3D projections have been around for decades. You may have seen a 3D movie in cinema, but have you ever wondered why and how 3D glasses work? At Abernethy Owens, we are the leading independent optometrists in WA, providing a highly personalised eye care service. When it comes to 3-dimensional imagery, there are a few different factors that need to work together in order to present you with a specular visual display, read on to find out more about this incredible technology.

Human Eyes Have Binocular Vision

Binocular vision gives you depth perception and allows you to tell which objects in your line of sight are closer or farther away. It relies on the distance between your eyes to present you with two different perspectives on the same thing. In order to see a movie in 3D, each of our eyes needs to see something different, and we need to stop our brain from merging them together. When you look at a 3D projection through 3D glasses, your brain is using a technique called stereoscopy to create the illusion of depth. This is where the brain takes two separate images and processes them so that the image appears to “pop” out. If you take off your glasses while watching a 3D movie, you’ll find that it is impossible focus on the image displayed. This is because these movies are forcing two different layers of imaging on top of each other to create a 3-Dimensional effect.

The Invention of 3D Glasses

Scientists have known for many years that different colours enter the eyes in waves of different speeds and intensities – their individual wavelengths. The shortest wavelength of visible light is violet and the longest wavelength of visible light is red. When looking at 3D imaging, scientists began to work with different colours to enhance these images. During their research, they found that using glasses with two different coloured filters stopped the eyes from merging the two separate images together to create one full image. Instead, the filters only allow one image to enter each eye, and the eyes layer these two on top of each other to create more depth to the image.

The 3 Types of 3D Glasses

There are generally three types of 3D glasses - anaglyph, polarized, and shutter. Each uses different methods to bring flat images on your screen to life.

Anaglyph 3D Glasses - the most common type, and the iconic image many think of when hearing about 3D glasses. These utilize special red/cyan lenses to interpret the image. These lenses produce the images you see by colour filtering the layered image that you’re actually looking at. While one lens filters out all the red in an image, the other lens filters out the cyan, causing your brain to see the picture in 3D.

Polarized 3D Glasses – the optimal choice for IMAX 3D movies and they’re the grey lens glasses you normally get in cinemas today. Instead of restricting the light that enters your eyes by red and blue, they have a yellowish brown tint. The image on the screen also has a role to play. In addition to the polarization on the glasses, the projected image is actually two images that are superimposed on the same screen through an orthogonal polarizing filter. The glasses, which have the same type of filter, allow each eye to see the two individual images on the screen.

Shutter 3D Glasses - considered the most advanced type of 3D glasses available today. While the other two types use passive 3D, shutter glasses utilize active 3D. They don’t use filtered images or colours to create a three dimensional effect, they work through LCD screen technology that darkens each lens, alternating the left and the right. This darkening happens so quickly that you don’t notice the effect unless you’re paying close attention.

All types of 3D glasses work by making each eye see two different things. Your eyes seeing different things tricks your brain into interpreting them in spectacular 3D!

If you are looking for professional and friendly experts to take care of your eye health, get in touch with Abernethy Owens today. As WA’s trusted independent optometrists, we are proudly WA owned and operated and we offer professional eye care with style – book an appointment online today.