3D Displays May Be Hazardous To Young Children 386
SchlimpyChicken writes "Turns out 3D television can be inherently dangerous to developing children, and perhaps to adults as well. There's a malaise in children that can prevent full stereopsis (depth perception) from developing, called strabismus or lazy-eye. It is an abnormal alignment of the eyes in which the eyes do not focus on the same object — kind of like when you watch a 3D movie. As a result, depth perception is compromised. Acting on a hunch, the guys over at Audioholics contacted Mark Pesce, who worked with Sega on its VR Headset over 15 years ago — you know, the headset that never made it to market. As it turns out, back then Sega uncovered serious health risks involved with children consuming 3D and quickly buried the reports, and the project. Unfortunately, the same dangers exist in today's 3D, and the electronics, movie, and gaming industries seem to be ignoring the issue. If fully realized, 3D just might affect the vision of millions of children and, according to the latest research, many adults, across the country." The Audioholics article is a good candidate for perusing with Readability — the pseudo-link popups are blinding.
Re:They -buried- the reports? (Score:5, Informative)
Of course they buried the reports. Sega didn't want the PR of "We make headsets that screw up kids' eyes lol"
What they DID do right, is never release the product. That was the first right thing to do. It would've been nice if some non-Sega-related entity were to release the reports, but that's secondary. It's by FAR a safe bet that no company today would ever do the same. The reports would still get buried, and non-disclosure agreements would be plastered on every researcher, but the product would be on every freakin' shelf from Wal-Mart to Best Buy.
better sources would be nice (Score:2, Informative)
Re:Sega probably buried the reports because... (Score:5, Informative)
This would affect most 3D displays, but not all (Score:4, Informative)
Auto-stereoscopic displays don't require glasses and wouldn't cause this sort of issue if I'm understanding the vision problems correctly.
http://en.wikipedia.org/wiki/Autostereoscopy [wikipedia.org]
Not all companies are trying to hide this. (Score:5, Informative)
Driving after watching 3D TV (Score:5, Informative)
I went to a talk last week given by BBC R&D with the Institute of Engineering and Technology and the Royal Television Society. The problem with children was raised, however research that is currently being conducted and is finding that children adapt better than adults. We will have to wait until they are finished and peer reviewed however.
What is more worrying is driving a car after watching 3D TV. You eyes focus on a 40 inch screen 3-4m away, however you brain thinks you are looking in the distance because the image is converging at a different point (not 3m away). This isn't really a problem in the cinema as the distance to the screen is far greater, as at 50 feet your eyes are focused at almost infinity. Stepping out of the living room and in to a car can easily have an effect on judgement of distance, and give you headaches.
Headaches, incidentally, is a problem with all consumer home 3D TVs. They will give the vast majority of people a headache after 10 minutes. That's a fact!
E10+ is sufficient (Score:3, Informative)
Virtual Boy hardware was rated 7+ in its manual.
Besides, this is a display panel, not goggles. Setting stereo separation to 0 would make it little different from a DSi with a better video chip.
Re:Driving after watching 3D TV (Score:3, Informative)
Oh, and "3D TVs" are not 3D, they are stereoscopic TVs.
R2D2 has a 3D TV with his hologram projector. That for a 3D TV is what we all aspire to. :)
Re:This would affect most 3D displays, but not all (Score:3, Informative)
The issue should apply to pretty much all normal 3D tech, as all they do is simply get different images to each eye. It doesn't really matter how exactly they do that, as the core problem is that your eyes have to focus on the 2D screen, while you are looking at objects in front or behind the screen. Thus where your focus is and where it should be are different places.
Not sure about holograms, they work a little different, so they might be fine. But as we don't have interactive holographic displays thats a moot point.
Re:This would affect most 3D displays, but not all (Score:4, Informative)
Doesn't this issue involve the eyes not focusing properly o a point in space?
The issue is that you are looking at an 3D object say 1 meter in front of you, while you are focusing on a screen that might be 3 meter away from you. Thus your depth perception gets a little confused and possibly permanently damaged when you do that stuff to much while your brain is still developing. This issue is exactly the same when you use an auto stereoscopic display instead of shuttle glasses or polarized lenses. The offset between both images is exactly the same as on any other type of 3D screen, as thats where the 3D comes from.
Re:Just rate it M for Mature (Score:1, Informative)
It was supposed to be a dig at how putting an age limit would be useless since people already complain about how M rated games reach chilluns because THEIR PARENTS BUY IT FOR THEM.
I guess my attempt at subtlety was too subtle or just bad.
Re:They -buried- the reports? (Score:2, Informative)
Only half 3D ! convergences does not match focus (Score:3, Informative)
The ayes react to the proximity of an object in two ways
The first in convergence : both eyes make a slight angle in theay a telemeter would do. this is bound to the distance or at least the PERCEIVED distance when each eye has a different image.
The second is focus : if the object is 50cm away, the focus of each eye is set to 50cm.
In normal vision, these two actions are synchronzed, and many years of living with it has helped us to do so.
Unfortunately, in 3D vision, convergence asks something while focus asks for something else (you see the object at 50cm, but each eye should focus on the screen nevertheless), which is the reason why this false 3D is far from perfect and can be just as painful as eye convergence reeducation. In fact, it is ye convergence DISeducation.
Accomodation and Vergence (Score:4, Informative)
I believe most 3D will "make your eyes hurt" for extended use until they solve vergence [wikipedia.org] and accomodation [wikipedia.org] issues. While there is some work (e.g., accommodation display at Fraunhofer [fraunhofer.de] and some work at HITlab [washington.edu]) to resolve these, I'm afraid we might not see the results of these at Best Buy anytime soon.
Having demonstrated 3D technology to hundreds of adults and kids, my experience has been that kids below 12 _generally_ don't seem to "get" 3D. Perhaps it's their visual system, or perhaps it's because the inter-pupillary-distance (IPD) is wrong on most systems for how far apart their eyes are. I don't this they'll be missing out on too much if they skip out on the 3D games until their visual systems catch up with the tech.
All this aside, I'm personally thrilled that all this 3D technology is becoming mainstream, but I wouldn't (and wouldn't recommend for anyone to) use the 3D technology for more than a couple of hours a day at most. Still, the fear-mongering articles and the 3-D bashing that accompanies them (probably by people who can't see the 3D effect) kind of ticks me off..
Re:Virtual vs. Real (Score:2, Informative)
Re:They -buried- the reports? (Score:2, Informative)
Strabismus is not "lazy eye" (Score:1, Informative)
I'm a researcher who used to study strabismus and amblyopia.
There are a lot of factual errors in the original post. First of all, strabismus is an eye turn, not a "lazy eye". Amblyopia is what is called "lazy eye". It is not "malaise" that causes strabismus or amblyopia. Amblyopia is am abnormal development of vision during infancy or early childhood due to improper visual inputs from strabismus, anisometropia (unequal refractive error in the two eyes), high refractive error in both eyes, infantile cataract, corneal opacities, or ptosis (eyelid drooping). Strabismus can be due to convergence problems (ability to use the two eyes as a team), uncorrected hyperopia causing excessive accommodation and through the neurological linkage between accommodation and convergence or, in infancy, due to other factors.
3D movies do not cause strabismus or amblyopia. However, people who have binocular vision problems will have increased asthenopia (eyestrain) when viewing them.
Re:This would affect most 3D displays, but not all (Score:3, Informative)
Re:They -buried- the reports? (Score:3, Informative)
A major difference between the two technologies is focal depth, among others.
That said, even 'how to prevent eyestrain' manuals for office workers tell you to look away from the screen periodically to refocus your eyes and prevent strain.
Re:They -buried- the reports? (Score:4, Informative)
This article on the Pinto defects explains it well
http://www.engineering.com/Library/ArticlesPage/tabid/85/articleType/ArticleView/articleId/166/Ford-Pinto.aspx [engineering.com]
BENEFITS
Savings: 180 burn deaths, 180 serious burn injuries, 2,100 burned vehicles. Unit Cost: $200,000 per death, $67,000 per injury, $700 per vehicle.
Total Benefit: 180 X ($200,000) + 180 X ($67,000) + $2,100 X ($700) = $49.5 million.
COSTS
Sales: 11 million cars, 1.5 million light trucks.
Unit Cost: $11 per car, $11 per truck.
Total Cost: 11,000,000 X ($11) + 1,500,000 X ($11) = $137 million.
Trouble for ford was killing and maiming customers becomes a lot more expensive when its known you are aware of the problem.
presumably SEGA took this lesson on board and discontinued development.
Re:This would affect most 3D displays, but not all (Score:3, Informative)
The only difference is the channel separation method: glasses are filtering out the images for the left and right eye, while for autostereoscopy it is a grazing that directs left and right images to your left and right eyes.
An interesting difference though, is that you are either focusing on a very far screen or at infinity at the theatre, or very close in case of the 3DS.
Here is the relevant part of TFA:
Clear single vision of an object requires both accommodation and vergence to operate. The process of accommodation, in which the eyes focus on near objects and relax focus for distant objects, is driven by image blur. The primary goal of accommodation is to minimise the blur. The vergence system operates to produce a single perceived image from the two retinal images, by bringing the images close to the fovea of each eye so that they can be fused into a percept of a single object at a given depth. During this process the eyes converge upon near objects and diverge to fixate upon far objects. The accommodation and vergence systems interact via neural cross-links, so that a response in one system drives a corresponding response in the other. While it is known that the cross-links are open to adaptive change the process and limits of adaptation are not fully understood [Rushton & Riddell 1999; Wann & Mon-Williams 1997].
Problems of stress on the visual system have been most obvious in HMDs. While poor engineering design or incorrect calibration for the user can be a source of visual stress, a problem less easy to avoid is the challenge to the accommodation-vergence cross- links. Current stereoscopic VR displays provide an illusion of depth by providing each eye with a separate 2D image on a fixed focal plane. The mechanisms of binocular vision fuse the images to give the 3D illusion. Because there is no image blur, the eyes must make a constant accommodative effort. But at the same time the images stimulate a changing vergence angle with changes in apparent depth, so that the normal cross- linked relationship between the systems is disrupted [Mon-Williams & Wann 1998]. The problem is not limited to HMDs as any stereoscopic display, from a stereoscopic desktop to immersive systems such as the CAVE, uses the same display method [Wann & Mon-Williams 1997]. Within certain limits the visual system can adapt, as shown by results of orthoptic exercises and of adaptation to different prisms placed in front of each eye. However, whether the changes are long term or whether there can be dual adaptation to both the real and virtual environments has not been established [Rushton & Riddell 1999].
Re:They -buried- the reports? (Score:5, Informative)
The VR headset that study was about functions with a completely different mechanism than most modern 3d systems. In 3d movies, or on the Nintendo 3ds, you are NOT focusing on two different objects. It's no different than looking at a mirror, as another poster pointed out. The study involved a headset with two screens, one for each eye.
You'll probably claim I'm a shill, rather than admit this study is irrelevant.
Re:They -buried- the reports? (Score:5, Informative)
Good thing this guy remembered!
"This guy" is Mark Pesce [markpesce.com], was the co-creator of VRML, and has developed and taught courses in 3D development at the university level for most of a couple of decades now.
Re:You focus on different objects? (Score:2, Informative)
Actually, the lens has to focus on the distance of the physical screen, or you don't get a sharp image. The relative orientation of the eyes, however, will correspond to the apparent position of the 3D object shown.
Re:I can't see the logic behind this... (Score:2, Informative)
Well, that alone would not be a problem, because in both cases we only get the light which hits our eyes. If the light from the real object and from the movie object were exactly the same, than for our eyes it would be as if the object were where it appears to be, and everything is OK. However, in reality, it isn't like that. Each single eye image already contains a depth information due to the divergence of light rays (the ray approximation is still good here). This depth information matters because it determines how the lens in your eye has to be focused to get a sharp image. For 3D movies, this "focal depth" still is the distance of the screen.
On the other hand, the binocular vision allows to extract depth information from the displacements between the left-eye and the right-eye image. This is what our 3D perception comes from, and this is what the 3D movies use. So the "binocular depth" is wherever the object appears to be in the 3D movie.
Now in the real world, "focal depth" and "binocular depth" are the same. Therefore they are normally coupled in your vision system (focusing at an object at different distance means both moving the eyes so that the displacement is zero for the desired distance, and changing the eyes' lenses so that images from that distance are sharp). This link breaks for 3D movies (you still have to move your eyes, but you don't have to re-focus the lens).
Re:This would affect most 3D displays, but not all (Score:3, Informative)
If seeing in 3D depending matching convergence and focus, then 3D displays wouldn't work for anybody, nor would binoculars. The reason 3D displays, binoculars, and older 3D technologies like the stereoscope [wikipedia.org] do work is that your brain identifies similar elements in the field of view, and assumes that they are different perspectives on the same object. Focus provides only minor hints, and only for objects up close. This is why your depth perception can easily be confused by repetitive patterns like chain link fences, or those "Magic Eye" pictures, where your eye ends up converging the "wrong" images, ignoring focus cues.
Re:They -buried- the reports? (Score:2, Informative)
The complaint is not new either (Score:3, Informative)
Mark has been talking about "binocular dysphoria" [wikipedia.org] for some time now (e.g. Wired article [wired.com] from 1994). Thing is, it seems nobody else is.
The effect certainly exists (I've experienced it myself, though only for a matter of seconds), but it remains doubtful as to how significant it is. There are various medical studies that confirm the resiliency of human vision to this type of effect, but it seems no studies have been found or cited that show any lasting problems (with the possible exception of this informal commercial Sega report that Mark was involved in, if it's ever verified).
My take is, if you're a cautious type, there's no need to rush your kids into these things - it's just one form of entertainment, after all. Further study certainly wouldn't hurt. OTOH, artificial stereopsis has been around for literally hundreds of years (some French painter invented [wikipedia.org] the parallax barrier method in 1692) with no reported long-term effects since then. Anecdotally, others here have mentioned viewing stereo material day in, day out for years with no ill effects either, so if there are any ill effects they're probably subtle.