posted 03-12-2010 09:29 PM                   

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A few days ago I found an odd package waiting in my mailbox. One of the commercial TV networks got my postie to deliver a pair of 3D glasses - very old school, with separate red and blue lenses. I spent a few moments assembling them, and presto! I looked like I'd just walked out of a showing of 1954's Creature From the Black Lagoon.

Now that James Cameron's Avatar has become the highest-grossing film in history, 3D is very hot. The hottest new toys unveiled at this year's Consumer Electronics Show were 3D television sets, 3D Blu-Ray players, and comfortable 3D glasses for the lounge room. At least three US-based cable networks have promised 3D broadcasts will begin sometime this year - for the few people who have 3D television sets. Everyone in the consumer electronics industry sees this as the Next Big Thing: now that everyone has purchased big, flat-screen TVs, 3D is the next logical step, the necessary upgrade that keeps us all on the treadmill of progress. The movie studios have also gotten behind 3D in a big way. Just last week Warner Brothers announced that the two final Harry Potter films will be shot in 3D.

Is this the decade of 3D? It might look that way, but we'd all better hope it turns out quite differently. You see, 3D is not good for you.

How can this be? Isn't the real world in 3D? Yes, the real world of objects is definitely three-dimensional. But that's where the similarity ends. What you're shown on a movie screen - or soon, a television - is not true 3D. That's the source of the problem.

Back in the 1990s I did a lot of development work in virtual reality - another technology destined to be the Next Big Thing. I helped Sega develop a head-mounted display (fancy VR headgear) that could be plugged into the Sega Genesis (known as the Mega Drive in Australia). Everything was going swimmingly, until we sent our prototype units out for testing.

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.

This doesn't matter too much if you're going to see a movie in the theatre - though it could lead to a few prangs in the parking lot afterward - but it does matter hugely if it's something you'll be exposed to for hours a day, every day, via your television set. Your brain is likely to become so confused about depth cues that you'll be suffering from a persistent form of binocular dysphoria. That's what the testers told Sega, and that's why the Sega VR system - which had been announced with great fanfare - never made it to market.

Video games are one of the great distractions of youth. Children can play them for hours every day, and our testers realized that children - with their highly malleable nervous systems - could potentially suffer permanent damage from regular and extensive exposure to a system which created binocular dysphoria in its users. This is the heart of my concern, because 3D television is being pitched as an educational medium - Discovery Channel has announced 3D broadcasts will begin mid-year - and that medium could damage the growing minds it is intended to enlighten.

All of this is rolling forward without any thought to the potential health hazards of continuous, long-term exposure to 3D. None of the television manufacturers have done any health & safety testing around this. They must believe that if it's safe enough for the cinema, it's fine for the living room. But that's simply not the case. Getting a few hours every few weeks is nothing like getting a few hours, every single day.

One of two things is about to happen: either 3D television will quickly and quietly disappear from the market, from product announcements, and from broadcast plans, or we'll soon see the biggest class-action lawsuit in the planet's history, as millions of children around the world realize that their televisions permanently ruined their depth perception. Let's hope 3D in the home dies a quiet death.

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posted 03-14-2010 04:17 PM                   

The author of the article is freely extrapolating the much more complex scenario of virtual reality (especially early attempts, where depth cues from extra head movement, moving shadows, etc, were grossly off/ignored by the hardware) with casual stereoscopic viewing on fixed screens. That much is true.

Still, there is a point that enough data doesn't exist (AFAIK) on the lack of potentially bad side-effects on developing visual systems in children when exposed to many hours every day of stereoscopic 3D viewing, especially if shot wrong (i.e. with vertical parallax, excesive divergence or whatnot) or if it's computer generated (i.e. videogames).

The studies that do exist seem to point to temporary impairment of some visual parameters. But they weren't long term-long exposure.

3D videogames tell your brain that there is a certain interactivity matched to a depth perception that is different with real life. You can't really "see around the objects" by moving your head slightly, etc in stereoscopic games.

The OP worried that if you do this 3D videogame playing many hours a day the brain in children will stop interpreting the depth cues in nature the correct way.

There is a point there. We just need more research to figure out how much this could be a problem or hardly at all.

Think about it. Until now, through history, children have never (really) been exposed massively to potential stereoscopic anomalities like pseudoscopy, divergence, accomodation breakdown, infinite depth of field from CGI tied-to-stereopsis, wrong perspective-to-stereopsis relations from non-orthoscopic shots/aberrant lenses/extreme focal lengths, etc, etc. Even just the accomodation breakdown has been proven to temporarily affect adversily visual accuity.

Subject a child to 3 hours a day from age 5 til 12 and who knows what can happen ... There is a good chance that nothing good.

I agree is more a concern in stuff like videogames and virtual reality or badly shot 3D material, but still worth considering.

Otherwise, the article is bollocks

Responses like this, though, don't bring a lot of confidence:

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Panasonic are well and truly on the 3D TV bandwagon. This morning I had the opportunity to check out a pre-production sample of a 50-inch 3D plasma at Panasonic HQ, and asked them about concerns over Binocular Dysphoria, as brought to our attention by Mark Pesce on Byteside the other week. Here was their response:

To be fair, I sort of put Panasonic’s Director of Consumer Electronics Paul Reid on the spot when I asked whether there had been any research done to test the potential damage done from continuous 3DTV watching, but this was his response:

“I don’t have any information at hand on any specific research studies, but one thing I could say is that Panasonic’s been developing 3D for many, many years and we’ve been evaluating, testing, viewing tens of thousands of hours of testing and we’re absolutely confident that our 3D solution will meet every safety standard and we don’t see any issue in that regard.

Fundamentally, we would encourage anyone who feels any sense of discomfort watching 3D to stop watching. And if they’re a little bit unsure, then they should spend time in a retail store for themselves viewing 3D and come to their own conclusion.”

Panasonic’s Group Marketing Manager for Viera Matt Pearce added:

“I think the other important point is that this is a 2D TV as well. It’s an option, it doesn’t have to [display] 3D, you can watch the content in 2D as well…

It’s safe to say obviously that if there were issues we’re not going to bring something to market.”

They’ve promised to look into the issue a little more for me to see whether or not Panasonic’s done any research during the development of the technology into this, and I’ll obviously let you know their response.

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We've done testing, says Sony

Sony, which is planning to launch several 3D TV models in Australia this year, said it had already conducted safety tests on its technology.

"We’ve had a third party, specialised research institute to study the impact of 3D viewing to people’s health and received a report that they did not find any change of health condition which should be deemed as an issue," it said.

However details of the safety report, including whether it addressed binocular dysphoria, were not available.

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posted 03-14-2010 04:53 PM                   

quote: Claude S. Ayakawa

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If long tern exposure was harmful, how is it I had never heard of any class action suits against the promoters of the festival for making people watch 3-D movies for about three straight days on a continuous basis?

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Claude,

Most people did not watch all the films every single day.

Those of us who did, probably ended up with our vision temporarily screwed. I couldn't really tell you. It was already night time when out and I just walked straight to the hotel and went to sleep or worse, jumped over to the Dome theater for cinerama or whatnot.

Just watching 3 regular 2D films in a theater everyday for a week will likely give everybody some temporary eyesight discomfort.

The problem is likely not with the adults nor with watching a couple of 3D films a week. It could come, though, from watching hours of TV a day at very young ages for years. Or maybe not. We just don't know. It has never been tried, AFAIK, but there are some indications it could lead to worse developed visual systems in depth perception/assessment. Probably only very subtly and nothing to worry about, but who knows. Maybe it will actually INCREASE the ability to assess depth and distances.

posted 03-14-2010 07:57 PM                       

quote: Claude S. Ayakawa

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If you hate 3-D, that is ok with me but stop telling all of us who love 3-D that it is bad for us.

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