May 02, 2011

from PreventDisease Website


In the recent past there have been a number of amazing innovations in the world of 3D entertainment, from movie theatre technology to what we see at home, to highly developed games and now televisions.


But researchers are now sounding the alarms stating that there are clear health risks when using such technology.

Researchers at the University of California Berkeley have found that viewing 3D movies with 3D glasses can strain the eyes by changing the relationship between the eyes and the brain. This can result in headaches and blurred vision, and it seems that the problem is particularly troubling for young children.


Those who do experience these kinds of painful side-affects should limit their 3D viewing, as long-term results havenít been found.

Below is an example of a 3D Movie trailer on YouTube which is distorted without 3D glasses but an entirely different experience with the glasses... but at what cost?

3D Video Anaglyph 3D Movie Trailer





All the big boys - Samsung, Sony, Panasonic - are betting that people will want to put a 3D capable television in their home.


But is it safe? No, says Mark Pesce.


And he would know:

he started one of the first virtual reality companies in the early 90′s and worked closely with Sega to develop a virtual reality headset for their Genesis system. Only, that headset was never released, as a result of a study done by SRI that was commissioned by Sega.

Pesce says that the study found that a significant percentage of users maintained depth perception issues anywhere from 15 minutes to hours after taking the headset off. This is why Sega never released it.

Virtual reality headsets use the same technique for displaying 3D as we find in movies or 3D television sets - parallax. They project a slightly different image to each one of your eyes, and from that difference, your brain creates the illusion of depth. That sounds fine, until you realize just how complicated human depth perception really is.


The Wikipedia entry on depth perception (an excellent read) lists ten different cues that your brain uses to figure out exactly how far away something is.


Parallax is just one of them. Since the various movie and television display technologies only offer parallax-based depth cues, your brain basically has to ignore several other cues while you're immersed in the world of Avatar. This is why the 3D of films doesn't feel quite right. Basically, you're fighting with your own brain, which is getting a bit confused. It's got some cues to give it a sense of depth, but it's missing others.


Eventually your brain just starts ignoring the other cues.

That's the problem. When the movie's over, and you take your glasses off, your brain is still ignoring all those depth perception cues. It'll come back to normal, eventually. Some people will snap right back. In others, it might take a few hours. This condition, known as 'binocular dysphoria', is the price you pay for cheating your brain into believing the illusion of 3D.


Until someone invents some other form of 3D projection (many have tried, no one has really succeeded), binocular dysphoria will be part of the experience.

The thing is, ďbinocular dysphoriaĒ does not appear to be a recognized medical term, even though Pesce has been warning about it as early as this 1994 Wired article.


The American Optometric Association doesnít recognize it, and the TV manufacturers clearly arenít concerned because they arenít doing any testing. But just because it isnít recognized yet doesnít mean itís not a real danger - especially since 3D TVs are about to enter mainstream entertainment.

What should be done about the dangers of 3D? Well, the headaches and dizziness that some viewers experience can be reduced simply by lessening the amount of time spent using 3D technology, and those who experience the effects for a long period of time should refrain from exposing themselves.

No matter, 3-D is here to stay. Experts predict that 3-D television will be a major trend in about five years.


Buyer beware...