Is It Possible to Watch 3D Without Glasses?

The state of glasses-free 3D viewing

3D viewing options available and in use for the home or cinema requires the use of 3D glasses. However, there are technologies in various stages of development that enable a 3D image to be viewed on a TV or other video display device without glasses.

Family Watching TV With 3D Glasses.
Getty Images - Credit: vgajic - Collection: E+ - 185121753

The Challenge: Two Eyes, Two Images

The main issue with viewing 3D on a TV (or video projection screen) is that humans have two eyes, separated by a couple of inches.

The reason we see 3D in the real world is each eye sees a slightly different view of what is in front of it and transmits those views to the brain. The brain combines the two images, resulting in viewing a natural 3D image correctly.

However, since traditional video images displayed on a TV or projection screen are flat (2D), both eyes see the same single image. Although still and motion photography "tricks" can provide some sense of depth and perspective within the displayed image, there are not enough spatial cues for the brain to accurately process what is being viewed as a natural 3D image.

How 3D Traditionally Works for TV Viewing

What engineers have done to solve the problem of seeing 3D from an image displayed on a TV, movie, or home video projector and screen is to send two slightly different signals that are each targeted to your left or right eye.

Where 3D glasses come in is that the left and right lenses see a slightly different image. Your eyes send that information to the brain — the result, your brain is fooled into creating the perception of a 3D image.

This process isn't perfect, as the information cues using this artificial method are not as detailed as the cues received in the natural world, but if done properly, the effect can be very convincing.

The two parts of a 3D signal that reach your eyes, requires the use of either Active Shutter or Passive Polarized Glasses to see the result. When such images are viewed without 3D glasses, the viewer sees two overlapping images that look slightly out of focus.

Progress Towards Glasses-Free 3D

Although glasses-required 3D viewing is accepted for the movie-going experience, consumers have never totally accepted that requirement for viewing 3D at home. As a result, there has been a long-running quest to bring glasses-free 3D to consumers.

There are several ways to execute glasses-free 3D, as outlined by Popular Science, MIT, Dolby Labs, and Stream TV Networks.

Shown below is an example from Stream TV Networks (Ultra-D) of how a TV needs to be constructed so that it can display 3D images for viewing without the need for glasses.

Inside a Glasses-Free 3D TV
Stream TV Networks

Glasses-Free 3D Products

No-glasses 3D viewing is becoming available on some smartphones and tablets and portable game devices. However, to view the 3D effect, you have to look at the screen from a specific viewing angle, which is not a big issue with small display devices, but when scaled up to large screen TV sizes, it makes implementing glasses-free 3D viewing very difficult, and expensive.

No-glasses 3D has been demonstrated in a larger screen TV screen form factor as Toshiba, Sony, Sharp, Vizio, and LG have all showed glasses-free 3D prototypes at various trade shows over the years.

Toshiba briefly marketed glasses-free 3D TVs in a few select Asian markets.

However, glasses-free 3D TVs are marketed more to the business and institutional community. They are used mostly in digital signage display advertising. They are not generally promoted to consumers in the U.S. However, you may be able to purchase one of the professional models offered by Stream TV Networks/IZON technologies, which are available in the 50 and 65-inch screen sizes and carry very high price tags.

Ultra D Glasses-Free 3D TV
Stream TV Networks

These sport 4K resolution (four times more pixels than 1080p) for 2D images and full 1080p for each eye in 3D mode. While the 3D viewing effect is narrower than viewing 2D on the same screen size set, it is wide enough for two or three people sitting on a couch to see an acceptable 3D result.

Not all glasses-free 3D TVs or monitors can display images in 2D.

The Bottom Line

3D viewing is at an interesting crossroads. Although TV makers have discontinued glasses-required 3D TVs for consumers, many video projectors still offer 3D viewing capability as they are used in both home and professional settings — however, that still requires viewing using glasses.

On the other hand, glasses-free 3D sets within the commonly available LED/LCD TV platform familiar to consumers has made great strides, but sets are expensive and bulky compared to their 2D counterparts. Also, the use of such sets is more confined to professional, business, and institutional applications.

Research and development partnerships continue. As a result, we may see a 3D comeback if the glasses-free option becomes available and affordable.

James Cameron, who sparked the "modern" use of 3D for entertainment viewing, is working on technology that may bring glasses-free 3D viewing to the commercial cinema.

This may not be possible with current projectors and screens, but large-scale parallax barrier and micro-LED display technologies may hold the key, so stay tuned...