3D movies, depth perception, stereopsis and binocular vision disorders

At the end of this post is an excellent movie about 3D Vision Syndrome, an eye movement disorder that prevents people from seeing in three dimensions normally.  3D vision is called "stereopsis" and people who can't see in 3D are called "stereoblind".

If you or your child don't experience 3D movies they way other people do, you may have a binocular vision disorder that needs to be treated with vision therapy.

Here are some previous articles we have written on 3D vision and depth perception:

What is 3D Vision Syndrome? 

Don't like 3D movies? You may have 3D Vision Syndrome

Take your kids to see "Thor": doctor's orders!

Life threatening disease found in girls eye - lack of 3D vision was the clue

Fixing My Gaze - Can you imagine not having 3D vision?

TED - ideas worth spreading - Susan Barry on how vision therapy gave her 3D vision

Take your kids to see "Thor": doctor's orders!

One of problems in diagnosing vision disorders in children is that children who have never had normal vision have no way to know that there is anything wrong with their vision.  They have always seen that way and they think that everyone else sees that way too.

Most optometrists can tell you a story of a young child, perhaps 5 or 6 years old who goes to the eye doctor because she is not picking things up in school and a visual problem is suspected.  It turns out that the child is severely myopic and has likely never even seen the faces of her parents beyond identifying them as a particularly shaped blurr.  It is a heart warming moment when the child sees her mother clearly for the first time!  Here is a video of Dr. Randahwa telling this story about what happened with a five-year old girl in our Vancouver opometry clinic:

The same is the case with patients who have strabismus or ablyopia.  While the former may present itself in the form of a noticeable eye turn, amblyopia (or lazy eye, as it is is sometimes known - a condition where one eye is not working properly and may even be legally blind) is not obvious.   Patients with these conditions suffer from binocular vision problems (when the two eyes do not work together properly) and will often have stereo vision problems that make it impossible for them to see in 3D.  The problem is that such a child will not be able to tell you that there is anything wrong with her vision, because it has been that way for her entire life.  Read my older post about the book "Fixing my Gaze" to learn about a famous case of 3D deficiency and how an optometrist used vision therapy treated the problem.

Lack or depth perception and 3D vision could be a sign of a potentially life threatening disease.  It could be caused by eye cancer shutting off communication between one eye and the brain.  Cancer such as this should be caught early before it causes noticeable vision changes - that is the key to successful treatment and the reason why annual eye exams for children are so critical.

3D movies (like Thor, pictured to the right) and video games are an opportunity for parents to test 3D vision.  If a child does not experience the sensation of objects coming out at her from the screen, she may have a binocular vision problem.  You can ask your child to reach out for an object that is popping out of the screen.  If she does not reach out or does so at inappropriate times, you should take her to the optometrist for clinical testing.  

You can also ask your child to describe what the 3D movie or game is like.  Be careful not to ask vague questions like, "is this movie different from an ordinary movie?"  The child will be wearing 3D glasses, which can alter color and so the movie will be different for those reasons alone. 

While 3D media offer parents an opportunity to catch a visual problem, parents can always, and should regularly visit their optometrist where visual disorders like strabismus and lazy eye are routinely tested and diagnosed. 

Properly functioning binocular vision is not just necessary for enjoying the latest entertainment but it is vital for learning, sports, driving and it is necessary for many careers (you can't be an eye surgeon without good binocular vision, for example).

For more information of children's vision, eye care, and children's optometry, please visit www.kidsvision.ca.

Related articles:

What is 3D Vision Syndrome?

Don't like 3D movies? You may have 3D Vision syndrome

Life threatening disease found in girls eye - lack of 3D vision was the clue

Fixing My Gaze - Can you imagine not having 3D vision?

TED - ideas worth spreading - Susan Barry on how vision therapy gave her 3D vision

What is 3D Vision Syndrome?

The proliferation of 3D media in movies, video games and in the classroom is bring a new vision disorder into focus: 3D Vision Syndrome, or 3DVS.  Here is a video produced by the American Optometric Association that does a good job of summing up lots of science and research into a short and easily understandable presentation:

3DVS  is comprised of a group of symptoms that, taken together, indicate a functional vision disorder while watching 3D content. Symptoms include but are not limited to visual discomfort and fatigue, headaches, blurred vision, eyestrain, diplopia (double vision), dizziness/nausea and vision induced motion sickness after watching a 3D movie, 3D television or atfer playing a 3D video game.

Most people with 3DVS have an problem with the the way their eyes work together or focus.  Eye movement problems like this are often classified as binocular vision problems, the most common of which is convergence insufficiency.  Binocular vision problems are effectively treated with vision therapy.  To read research studies on convergence insufficiency and binocular binocular vision, click here.

A famous case of a developmental optometrist using vision therapy to treat 3D vision problems was the subject of the book Fixing My Gaze as well as the New Yorker piece by Oliver Sacks titled "Stereo Sue".

Don't like 3D movies? You may have 3D Vision Syndrome.

Some people are watching Titanic 3D without 3D glasses.  Why would they do that?  They may have an emerging vision disorder.  To go with it, a new medical term is emerging: "3D vision syndrome".

3D vision syndrome applies to a collection of symptoms that some people (some estimates peg the number at millions of people) suffer when exposed to 3D media content.  3D vision syndrome is coming to attention now because 3D movies, television, and video-games and other 3D media devices and applications have recently proliferated and many people are discovering that they cannot comfortably experience 3D.

3D media has significantly affected how we interact with our world. New mechanisms for delivering 3D content appear frequently from movies to television to video games.  Can the 3D internet be far behind? 3D has come into our theaters, hour homes and now even our schools.  Many schools are now using 3D content to improve their ability to teach a subject and studies show that 3D is very effective in the classroom.  One study found that the use of 3D in school increased test results by 17%.

Unfortunately, many people have a hard time seeing simulated 3D.  Chances are you know someone like this.  When viewing 3D content many people suffer from a number of symptoms during viewing such as blurred vision, headache, double vision, dizziness and vision induced motion sickness.

Binocular vision dysfunctions are the usual culprit when someone has problems with 3D.  And the impact of binocular vision dysfunction is not just restricted to 3D.  Studies have show that people with binocular vision dysfunctions have lower academic performance. Fortunately, binocular vision problems are effectively treated with vision therapy.

A famous case of vision therapy treatment for inability to see in 3D is the that of "Stereo Sue", or Dr. Susan Barry, a neuroscientist who wrote the book Fixing my Gaze about how vision therapy cured her stereoblindness and enable to see in 3D for the first time in her life at the age of 48.  Her story was also the subject of an article in the New Yorker written by Oliver Sacks.  She also gave a TED talk on vision therapy:

Vision Source Vancouver optometrists have successfully treated a number of patients who have had little or no depth perception. For some of these patients, their stereoblindness was caused by strabismus (eye turn) and persisted despite 2-3 surgeries that attempted to fix the problem. First vision therapy was used to straighten the eyes (vision therapy has a 87% success rate in treating strabismus) and then a completely different course of therapy is prescribed to establish 3D vision and depth perception.

For more information on 3D vision, click here.

The best online resource for 3D vision and health is the American Optometric Association's 3D vision website at   http://www.3deyehealth.org/ .

Fixing My Gaze - Can you imagine not having 3D vision?

I just read an inspirational book called Fixing My Gaze about neuroscientist, Susan Barry, who was born with strabismus (an eye turn) and had lived all her life without stereo vision, meaning that she could not see in three dimensions.

She had three surgeries to "correct" the eye turn cosmetically but she still could not see properly and the eye was still turned, although less than before. She had lived this way for over 40 years until she met optometrist Dr. Theresa Ruggiero.

Dr. Ruggiero treated Susan with vision therapy and corrected the eye turn and allowed her see in three dimensions for the first time in her life. Can you imaging how her world was transformed? I've heard rumors of a "Fixing My Gaze" movie but have not been able to confirm them.

Here is what Susan Barry said in an interview with Scientific American about how the world looked different after vision therapy:

"For the first time, I could see the volumes of space between different tree branches, and I liked immersing myself in those inviting pockets of space. As I walk about, leaves, pine needles, and flowers, - even light fixtures and ceiling pipes - seem to float on a medium more substantial than air. Snow no longer appears to fall in one plane slightly in front of me. Now, the snowflakes envelope me, floating by in layers and layers of depth. It's been seven years since I gained stereovision, but ordinary views like these still fill me with a deep sense of wonder and joy."

Our vision therapy practice includes many patients with strabismus but all of them are very young (obviously it is better to fix the problem when a patient is young to save her from living years with the condition).

Susan Barry's story is remarkable in that she was in midlife when she received vision therapy. The conventional wisdom, now being disproved by new studies, was that after the age of 7 or 8 , the brain could not be trained (or "rewired") to see in new ways. The old scientific thinking was that after early childhood, the brain became fixed. In fact, Susan Barry herself and other scientists thought that it was impossible for her to ever see in 3D.

Now, we know that the brain exhibits neuroplacticity and that given the proper behavioural therapy, even adults can rewire their brains. This has given hope to many people who did not receive treatment for visual processing disorders at a young age. Now it seems possible that even older patients with amblyopia or strabismus and other binocular vision disorders can benefit from treatments like vision therapy.

You can hear interviews with Susan Barry and read more about her story at her website: http://www.fixingmygaze.com/.