Corrective lenses: A device created at the University of California at Berkeley corrects for a visual discrepancy normally experienced while viewing 3D.
Martin Banks, UC Berkeley
Researchers are studying whether viewing 3D causes eyestrain.
The success of 3D movies has been accompanied by complaints from some viewers of headaches and eyestrain. And with 3D TVs, Blu-Ray players, and games coming to the home this year, some experts are calling for more research into the possibility of eyestrain associated with 3D viewing, particularly on smaller screens that are closer to the viewer.
The eyestrain issue "has come up very recently, anecdotally, with people having symptoms of headaches after Avatar," says Michael Rosenberg, MD, and associate professor at Northwestern University's Feinberg School of Medicine. "It was the first time there was a 3D movie that attracted the volume of people it did and had the kind of advanced technology it did."
3D technology tricks the brain by showing the left eye one image and the right eye another. The brain layers these images together to produce a 3D image. For the latest 3D movies, polarizing glasses filter different images for each eye. In 3D TV sets, battery-powered active-shutter glasses open and shut many times a second in sync with the TV image to show each eye a different picture.
To look at a three-dimensional object in real life, a set of eyes must do two things. Firstly they must "verge"--rotate slightly inward or outward so that the projection of an image is always in the center of both retinas. Secondly, the eyes must "accommodate"--change the shape of each lens to focus the image on the retinas. "Without appropriate vergence, you would see double, and without appropriate accommodation, you'd see blurry," says Martin Banks, a professor of optometry at the University of California at Berkeley who is researching the effects of 3D on the visual system.
Artificial 3D causes "vergence-accommodation conflict," according to Banks, because viewers must focus at one distance (where light is emitting from the screen) but verge at another distance (wherever the 3D object appears to be in space). This difference in distance in 3D viewing may be the source of headaches and other discomforts, he says. "In 3D, the natural linkage between vergence and accommodation is broken."
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A significant portion of the population doesn't handle 3-d in the same way as the majority. How does the technology work on units that are equipped to display it for people that don't want their t.v. in 3-d ? Is 3-d content always displayed in 3-d or is there the ability to toggle back and forth without loss of quality?
Many of the 3D consumer TVs coming out are "3D-enabled." This means that the TV plays regular high-definition, 2D content, but a user can switch to watch 3D content if desired.
3D doesn't work for me... I get very nauseous watching 3D stuff.... I went to watch How to Train Your Dragon in 2d, because I couldn't handle Avatar...
3-D Televisions and human health
I think, it may be too early to make
conclusive inferences,not until
sufficient facts and concrete evidential
proofs are assembled that reflect world
wide identical human health defects.
It is known, as pointed out above,
that the newly designed 3D televisions
impose onto its customers and users,the
risk of multiple image discrimination
caused by screen polarization.It is,
therefore, not out of place
to deduce that,any action, or foreign body,
in excess of the ordinary,either,outside,or
within the human body system,and with
potential capability of creating and
sending superflux of electrical
impulses to any portion of human brain
in unit time and in repetitive action,
which in turn, can create unusual state
of excitation, provokes abnormality
that manifests in humans in
form of headach.
Though distance as target of
investigative causes of rectinal strain
and stress,producing resultant
consequences of excessive excitation
to propel headach remains doubtful.
Nonetheless, a combination design of
high definition (HD), 2D and 3-D,all
in one television, provides extra
advantage and leaves the painful
choice of preference into the hands
of individual user(s).
Thus, any user who senses 3D television
viewing to pose sight constrains should
switch television setting from 3D back
to normal setting that is unlikely to
cause health discomfort.
Martin Atayo
(Technologist)
Washington, DC 20013
Im not to sure about the whole 3-d thing i mean it is cool in all but i always get headaches from it and i tend to get cross eyed ..im not to sure that this is a good thing becuase im not the only one who has these symptoms
People who can 'see' 3d in stereograms have trained their convergence and astra. To avoid
headache, make sure you can first 'see' stereograms.
People who can 'see' 3d in stereograms have trained their convergence and verge. To avoid
headache, make sure you can first 'see' stereograms.
The title of this article immediately caught my eye! How could a new TV technology, so cool and advanced, actually harm me? Reading this article brought me back to the days when kids used to sit to close to their TV, when in-fact they were actually far-sided. As technologies emerge, I am glad that doctors today are watching out for possible health concerns. In a way, it is an unspoken partnership for the betterment for society.
Dr. Brian Glassman
Ph.D. in Innovation Management from Purdue University
As a long time 3D (stereo pair) photographer, I can't argue with anything in this article. In fact I would suggest it contains nothing of which anyone, familiar with 3D presentation, is not aware. Stereo viewing is always unnatural, particularly the eye convergance / focal point violation. The human eye and mental processing system is, however, extremely adaptive and usually copes very well with these unusual situations.
Bill H.
2 eyes good, 1 eye bad, 3 eyes?
God help me but I prefer good books to all this new-fangled media. The German Johannes Gutenberg around 1440, a goldsmith by profession, developed a complete printing system, which perfected the printing process through all its stages by adapting existing technologies to printing purposes, as well as making ground-breaking inventions of his own.
I suspect some other mechanisms are involved too...
Besides the "focus on the screen" versus "automatically focus on the implied 3-D distance" conflict (if you cannot see "Magic Eye" images, this is probably a major issue for you), I would lay odds on there being other problems reported if the viewer has any tendency to tilt their head while watching.
If using polarization, that tilt is going to negate some of the separation, while if using LCD-frame-sync switching, that tilt is going to give you a three-dimensional effect as though your eyeballs were stacked one on top of the other. Headache-making even thinking about it.
Manufacturing in the United States is in trouble. That's bad news not just for the country's economy but for the future of innovation.
National Instruments has gathered customer information and data regarding some of the cost differences between building a custom solution versus using NI off-the-shelf tools. Using this data, we built the Graphical System Design ‘Build vs. Buy’ Calculator. The calculator can help show the financial differences between building a custom solution versus buying an off-the-shelf system. This paper discusses the benefits and drawbacks of both a traditional custom design approach and off-the-shelf embedded tools.
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chila
6 Comments
it's the polarization
Image discrimination through polarization is not perfect and that's the main cause of visualization problems.
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