This
is not intended as an insult, it’s a legitimate suggestion because we all experience
3D movies differently, and many of us have vision problems that can affect the quality
and way we experience 3D. We’re all aware of some film critics who have declared
that they don’t like 3D movies in general or that the 3D in a particular movie is
flat or the 3D adds nothing to the story. I would be interested in knowing if
some of these critics have deficits in binocular vision that limit their appreciation
of 3D if not their entire movie-going experience. An optometrist or
ophthalmologist who is schooled in binocular vision can determine if a person
has vision problems that prevent them from optimally seeing 3D movies. There
are also some easy tests you can try online that can assess
the quality of your 3D vision.
One
Film Critic’s Generalization about Hugo
I
read an article the other day by an unnamed critic who wrote that Hugo causes eyestrain. It would have
been more accurate if he had limited the statement to his own personal
experience rather than generalizing his reaction to the rest of the audience. Indeed, the film was nominated for 11 Oscars, so
clearly many other viewers did not experience visual discomfort from the
movie. It’s very possible that this
critic is lacking something in his ability to comfortably watch a 3D movie. Most
people who experience eyestrain in 3D movies are not stereo-blind. Their binocular vision can be normal during
everyday activities and they can comfortably look at a stereogram or single 3D
image, but they have difficulty in maintaining convergence and divergence of
their eyes when watching a 3D movie.
That’s
because a 3D movie requires our eyes to do something that does not happen routinely.
In the real world we focus and aim our two
eyes (converge or diverge) at the same location in space. For instance, we have to both focus and
converge on our thumb to see it in 3 dimensions. However, in a 3D movie focus
and vergence are completely separate. The
only place in a 3D movie where anything is in focus is on the movie screen. However, independently of focus, the amount
of disparity in an image pair signals the degree to which our eyes need to
converge or diverge, providing the brain with an illusion of where an object is
behind or in front of the screen respectively. How the brain and eyes try to
reconcile this dissociation between focus and vergence is believed to cause discomfort
in some people. However, this can often be treated through optometric vision
therapy.
So
we can’t really fault the critic for making the generalization that Hugo causes eyestrain because if he has
a problem dealing with the special type of binocular vision required in a 3D
movie, he is probably unaware of it and he likely thinks everyone is
experiencing the movie in the same way as him. However, if he has his vision
checked and, if necessary, gets professional treatment it could potentially
change his opinion of 3D movies and more importantly, he may start to
appreciate the new medium and have a more fulfilling movie-going experience.
My
Personal Experience with Partial Stereo Blindness
I’ve
had personal experience with vision deficits that can create a less than
optimal appreciation of 3D movies. When we were working on footage for Michael
Jackson’s This is It Tour in the very
early days of 2D to 3D conversion at Legend3D, I noticed that I was seeing
things in 3D differently than my stereo artists. When they would comment how
amazing a particular 3D converted shot looked, I could appreciate the stereo
but not sufficiently to share in their excitement. I certainly was able to
perceive 3D or I would not have been able to develop our software during the
preceding two years. However, it wasn’t until we started to assess creative
decisions as a team that it became most apparent I was missing something.
At
that point, I decided to have my binocular vision checked by an ophthalmologist. What I learned was that I had been fitted
with contact lenses using a corrective technique called “mono-vision” where my
left eye was corrected for seeing close and my dominant right eye was corrected
for seeing far. This type of eye correction is very commonly used for
nearsighted people. In essence, I was using only one eye for seeing far and one
eye for seeing close. You might think that walking around like this is far worse
than having just one good eye, but my brain adapted to the situation by partially
“turning off” or suppressing the blurry images coming from my non-dominant left
eye when viewing something in the distance. I was still able to appreciate 3D movies
and work in 2D to 3D conversion because I was forcing the use of my weaker eye
but to a much a lesser extent than my dominant eye.
Children
Have No Frame of Reference That They Might See the World Differently
This
was not the first time I discovered that I had vision problems of which I was
previously unaware. When I was in 3rd grade, my teacher noticed that
I was squinting at the blackboard and suggested to my parents that I have my
eyes examined. The optometrist told me that I was nearsighted and needed
glasses. Prior to this event, my parents
never had my eyes tested, and I never doubted that I was seeing the world in the
same way as all my friends. In other words, I had no frame of reference. However,
as soon as I was tested for glasses I was amazed at how clear and sharp the
world really was, and I recognized how much I was missing. Indeed, the same was
true of my 3D vision. As soon as the doctor changed my prescription so that my
eyes were perfectly balanced for seeing distance with a correction greater than
20/20, my perception of 3D vastly improved, and I developed acuity for 3D that today
very often exceeds that of my colleagues. I now have to wear glasses for
reading, but my distance and binocular vision is exceptionally sharp. This clearly
elucidated to me the fact that that no two people see 3D movies in quite the
same way.
Convergence
Problems and Stereo-blindness
My
eye condition is one of the most common visual anomalies that have the
potential of dampening the perception of 3D movies. More extreme conditions are
found in people with strabismus (crossed eyes or wall-eyes) who cannot
experience 3D vision because each eye is seeing a perspective so different that
the brain cannot fuse the two images into a single 3D image. As a consequence,
people with this neurologic condition depend on only one eye to see the world, rendering
them truly stereo-blind. These people literally exist in a flat visual world
with little if any sense of depth and volume.
Stereo
Sue: One Neuroscientist’s Journey into the 3D World
A
well-known neuroscientist, Dr. Sue Barry suffered from a congenital form of
crossed eyes, but like my experience in third grade, she thought everyone saw
the world the way she did. However, as a junior in college, she attended a
neurobiology lecture where experiments were described in which kittens with
experimentally created strabismus were found to lack the binocular neurons thought
to be necessary for 3D vision. There
appeared to be a critical period in the development of the brain during which
experiencing binocular vision is essential for the development of stereopsis or
3D vision. It was only then that Dr. Barry realized that she was no different
than those kittens and was very possibly permanently stereo-blind, never having
seen the world in three dimensions. As a child, she had undergone three
surgeries to adjust the muscles in her eyes so her gaze would become straight.
Unfortunately however, the outcome was more cosmetic than curative. To see in 3D in the real world, you have to
point your two eyes at the same place in space at the same time. While the surgery may have put her eyes into
better alignment, it did not teach her how to aim her two eyes simultaneously
at the same spatial location. When she had to focus on something, instead of
her two eyes equally converging inward on an object, one eye would look
straight at the object and the other would turn in. She could never adjust her
eyes so that images of objects would fall on the same corresponding place on
her two retinas. Therefore, fusion in her brain of the two perspectives into a
single 3D image was impossible.
Rewiring
the Brain to See 3D
At
the age of 48, Dr. Barry consulted a developmental optometrist who guided her
through a program of optometric vision therapy that taught her how to point her
two eyes simultaneously at the same point in space and fuse within her brain the
images falling on her two eyes. What is so fascinating is that over time she was
able to rewire her brain to fully experience 3D. While this is an anecdotal
example, there are other cases like Dr. Barry’s documented in the optometric
literature. These cases contradict the
cat study mentioned above as well as conventional wisdom in neuroscience that
there is a critical time in an infant’s development where the absence of
stereopsis creates stereo-blindness. In the case of Sue Barry, her congenital
condition of strabismus prevented her from seeing the world in three dimensions
from birth. Her poignant introspective journey into
this foreign 3D world and how it changed her life is fascinating. I invite my
readers to pick up her book, Fixing MyGaze, A Scientist’s Journey into Seeing in Three Dimensions. One
of the many examples of the wonders she experienced in this new world is her
description of seeing snow falling in three dimensions for the first time
rather than the way she saw it all her life as a flat sheet of various sized
white dots falling in front of her.
Today,
one of her favorite pastimes is going to 3D movies, and she recently told me
that she particularly enjoyed Hugo. She also told me that while she has always
enjoyed 2D movies, after gaining binocular vision she now experiences them
differently. Because of her new, real
world experience of seeing in stereo, her brain can now “fill in” the stereo
depth in a 2D movie that are suggested by monocular cues such as object
occlusion and motion parallax. People who have always had stereopsis have this innate
ability to “fill in” stereo depth in 2D images. However, you cannot experience a
sense of depth and volume in a 2D movie if you’ve never experienced that sense
of depth and volume in real life. We
take these things for granted so it never occurred to me that while still
stereo-blind, Dr. Barry did not experience a 2D movie the way people with
normal vision do.
The
passion in which she describes the immersive qualities of her new found 3D
existence is one of the best, real world examples of the importance of
binocular vision to our quality of life, and it points to the relative
difference of being engaged in a 2D movie or immersed in a 3D movie.
My
Message:
Everyone
in the business of story telling using 3D should have his or her eyes examined
for binocular vision. Correctly experiencing 3D movies requires two
eyes that are balanced for focusing images on the movie screen, and the ability of specialized
parts of the brain, tuned to disparity to fuse the two images on the screen
into a single 3D image, giving the impression of depth and volume. If there are
deficits in 3D vision they should be corrected so that both eyes are 20/20, or
at least evenly balanced, to reduce eye dominance. If the separation of focus and vergence
causes eyestrain, then optometric vision therapy might be the answer. As 3D becomes ubiquitous, people with 3D home
theaters and those that enjoy the 3D theater-going experience should have their
binocular vision checked as a matter of course on their next visit to the eye
doctor.
I
wish to thank Dr. Sue Barry for her review and insightful suggestions.
Dr. Sue Barry earned a Ph.D. in biology from Princeton University in 1981.
She has worked as a research neuroscientist at the University of Miami Medical
School in Florida, the University of Michigan in Ann Arbor, NASA’s Johnson’s
Space Center in Houston, Texas, and the Marine Biological Laboratory in Woods
Hole, Mass. Since 1992, she has been a professor of biological sciences
and neuroscience at Mount Holyoke College.
Dubbed
“Stereo Sue” by famed neurologist Oliver Sacks in a The NewYorker article by
that name, Sue Barry has gone on to write her own book “Fixing My Gaze” which describes the astonishing experience of gaining 3D stereovision
after a lifetime of seeing in only two dimensions. Her continued work in visual
neuroplasticity challenges conventional wisdom in neuroscience that the brain
is programmed for life during a critical period in childhood.
Additional references on Dr.
Barry’s
Revelatory Account of Discovering
3D Vision
1. Sue’s
website: www.stereosue.com
2. Fixing
My Gaze: http://www.youtube.com/watch?v=XCCtphdXhq8
3. "When Isthe Brain Fully Mature?" Psychology Today, August 17,
2011
4. "Chessand the Brain," Psychology Today, July 21, 2011
5. "ADefect That May Lead to a Masterpiece," The New York Times,
June 13, 2011
6. "Eyes onthe Brain: a Neurobiologist Explores the Amazing Capacity of the Brain toRewire Itself at Any Age" blog at Psychology Today.com
7. "Does PainChange the Brain?", blog at Psychology Today, May 28,
2011
8. "WereYou Nervous? Watching My Husband Blast Off Into Space", blog at
Psychology Today, May 16, 2011
9. "SeeingYourself Differently Through Reframing," blog at Psychology
Today, April 19, 2011
10. "In the Media: MHC's SusanBarry," Office of Communications, March 25, 2011
11. "Fear,the Eyes, and the Brain," Psychology Today, February 27,
2011
12. "Do WeFeel With Our Gut?" Psychology Today, October 26, 2010
13. "Susan R. Barry to be Featuredon Fresh Air," Office of Communications, August 12, 2010
14. "AStereoscopic Journey," Valley Advocate, September 10,
2009
15. "MHC'sBarry on Flexibility in the Adult Brain," Hartford Courant,
July 8, 2009
16. "The key
to 3-D vision," The Los Angeles Times, June 22, 2009
17. "MHC's Barry Publishes Memoir on3-D Vision," Office of Communications, June15, 2009
18. "MHC Professor Sue Barry Featuredin New Yorker," Office of Communications, June 14, 2006“
20. “Do you see what I see: A Scientist’s Journey into 3D" Interview of
Dr. Barry on NPR
