14/12/2010

The Lab Rat: What If You Could Only See the World in 2-D?

The Lab Rat: What If You Could Only See the World in 2-D?


LabRat
I don't see the world the way you do. I mean this literally. Like approximately 15 million other Americans, I arrived in November 1970 with strabismus — eyes that are visibly crossed (in my case) or, at the very least, not properly aligned. My parents got me into surgery around the age of 1 to fix, cosmetically, my severe strabismus so that I wouldn't look cross-eyed the rest of my life. But my eyes have never aligned properly.
Consequently, I lack binocular vision — what optometrists call stereopsis — which means I have very poor depth perception. Stereopsis is something you probably take for granted: the world looks 3-D to you, and when you put on those plastic glasses to see, say, Avatar, the arrows and hammerhead titanotheres pop out from the screen. If you have normal vision, even a simple glass on a table has a spherical quality to it. For me, the glass is 2-D, as though I were looking at a photograph. I enjoyed Avatar, but the mountain banshees were just flat creatures. (More on Time.com: It Had to Happen: Breasts in 3D)
When I was a child, it wasn't immediately obvious that my vision differed from that of others. But one day when I was about 10, my dad took me out to toss a football. On his first throw, the ball hit me squarely on the bridge of my nose and knocked me to the ground. My dad was horrified, and we realized something was wrong with my eyes.
Multiple sessions with optometrists ensued. One of the doctors suggested an eye patch on my left eye, the stronger one, so that the right eye could strengthen. Both eyes must be of roughly equal sturdiness to develop binocular vision, and my right eye was very weak. My mother vetoed the patch idea because I would suffer ridicule at school if I showed up looking like a pirate every day. I was already an awkward boy — incipiently gay, a poor athlete (thanks partly to the strabismus), and bookish — and she didn't want me teased further.
But the brain possesses remarkable plasticity, and eventually I learned to judge depth by monocular cues: trees in the distance look smaller than those just in front of me; shading changes as an object moves through light. I learned to notice that a ball thrown toward me grows larger as it approaches my waiting hands. But I was still terrible at sports; when I applied for a 1993 Rhodes Scholarship, I listed “hiking” in the section that required athletic accomplishments. Somehow, this embroidery was sufficient for me to win the scholarship. (More on Time.com: Why Surgeons Dread Redheads)
Years later, in 2006, The New Yorker published an article by Dr. Oliver Sacks, the acclaimed writer and neurologist. He wrote about Susan Barry, a woman who had been born with strabismus but, in her 50s, trained herself — after many hours over many weeks — to develop stereopsis. She did so by actively forcing her eyes to align. In his new book The Mind's Eye, Sacks expounds on Barry's experience. Barry spoke to Sacks of acquiring binocular vision in nearly religious terms. “The world really does look different,” she told him. Flowers looked “intensely real ... I could see the space between each [snow] flake, and all the flakes together produced a three-dimensional dance.”
I decided I had to try the same training that Barry underwent. I discovered that there are so many stereoscopic aficionados that there is even a New York Stereoscopic Society. The group, which has approximately 75 members, meets regularly to test the limits of their binocular ability by looking at complicated artwork and videos that can be seen only with advanced stereopsis. The interest in stereopsis dates back at least to the 19th century, when Oliver Wendell Holmes invented the Holmes Stereo Viewer (a kind of precursor to the View-Master) and wrote articles about stereopsis for The Atlantic. Nearly a century later, the first 3-D films began to appear.
One's eyes must align perfectly to see such art properly. If you can train your eyes to line up with precision, images jump with thrilling intensity from otherwise flat surfaces. Even if you have normal vision, you might have to practice alignment in order to see some of the more complicated 3-D artwork. These complex images aren't like watching Avatar with little glasses. Rather, even “ordinary things can look extraordinary,” Barry wrote to Sacks. After half a century, her world had changed. (More on Time.com: Digital Diagnosis 2010: The Most Popular Health Stories of the Year)
Intrigued, I made an appointment with Gerald Marks, an enthusiastic member of the New York Stereoscopic Society who owns a multitude of 3-D artwork and videos, many of his own creation. Marks, who used to teach printmaking at The Cooper Union in New York City, will turn 70 on Jan. 29. He is best known as the artist who created the 3-D videos that the Rolling Stones used during their 1989-90 tour. He did a “Painted Black” video that wowed fans around the world.
Marks has salt-and-pepper hair that grows in farcical tendrils. On the day I arrived in his studio, which is also his home, he wore cargo pants and a black fleece jumper and displayed an irrepressible passion for all his gadgets. He owns four computers and an expensive video projector mounted on the ceiling of one room. A sort of day bed with a pillow sits on the floor in front of the projector for maximum 3-D enjoyment. File boxes are stacked everywhere, and he maintains large plants in addition to all his tech equipment. I couldn't help but seeing him as a mad eye scientist even though he holds no optometry degree.
Marks put me through a set of experiments to see whether I could develop stereopsis. But I couldn't see even the simplest 3-D artwork with binocular vision even though the art had depth-perception cues such as some figures being smaller than others. I strained my eye muscles as hard as I could, but everything remained flat.
Finally, Marks gave me the toughest test: he showed me a random-dot stereogram, a stereo image he created that has no depth-perception cues whatsoever. To me, it looked like a Jackson Pollock painting: just squiggles on a flat plane. Marks told me that those who have trained themselves to have advanced binocular vision can see a box rise “above” that flat plane, and that when he moves his hand into the image, it appears as though his hand is moving into the box. (More on Time.com: Be Honest. Does this Study Make My Butt Look Big?)
Discouraged, I visited my optometrist of 13 years, Roy Cohen of Town Optical in midtown Manhattan. A few years ago, Cohen had used a new photographic technology to produce incredibly detailed images of the insides of my eyes.
It turns out I have a rare condition with a lovely name: Morning Glory Syndrome. Only about 1 in 2 million people are born with this congenital defect. There is no cure. The syndrome refers to the lack of nerve bundling in one or both eyes. (Thankfully, I got it only in my right eye.) When you are a fetus, the nerves in your eyes typically clench into a bundle. This allows the nerve endings to connect to the brain in an orderly fashion. Instead, my right eye developed with coloboma, a malformation that causes the nerves to splay into a wild configuration that means they can't reach the brain. The image looks like a bit like a morning glory flower.
In plain language, my Morning Glory Syndrome means I am mostly blind in my right eye. I was born not only with strabismus but with the syndrome. I was depressed to discover that I will never be able to enjoy a 3-D movie the way most people can or experience the transcendental vision that Sue Barry described with such avidity to Oliver Sacks. As Sacks points out, I will always have trouble threading needles — a huge chore for me — because I can see only the hole in the needle, not the roundness of the edges that makes it easier to position the thread.
But Sacks does offer a silver lining: although I am a writer, I might make a good photographer, filmmaker or painter. Such artists depend on flatness to make their images. In a footnote, Sacks points out that two Harvard neurobiologists have posited that, because of the deftness with which Rembrandt understood the flat plane, he was likely stereo-blind like me. The documentarian Errol Morris, who has an undeniable skill with images, also has strabismus so serious that he has only monocular vision. Morris told Sacks that the fascination with stereopsis was “bizarre.”
I am resigned to the fact that the world will always look flat to me, but that doesn't mean I don't see beauty. When it snows, I don't feel that I am among the snowflakes, but the way they fall on my shoulders is still moving. I may not see the world the way you do, but I appreciate its splendor just as much.
Follow me on Twitter @ JohnAshleyCloud.


Read more: http://healthland.time.com/2010/12/14/the-lab-rat-how-3-d-vision-works/#ixzz187QL3m7Z

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