Fixing My Gaze: A Scientist's Journey Into Seeing in Three Dimensions [Englisch] [Taschenbuch]

Do you have depth perception, that visual ability to judge what is closer and farther away?

If you are reading this review, the answer is yes. From the time of the Renaissance, artists have made use of cues for depth to endow their canvases with a sense of life: streets become narrower in the distance; subjects that are closer are also larger and overlap those that are behind; there is the slightest haze in the distance, a subtle indistinctness of form, a difference in shadow. These devices trick the mind into perceiving depth whether we have one eye or two.

There is a second, more vivid form of depth perception, however, which requires the use of two eyes. To experience it, try the following experiment: Hold your hand at a forty-five degree angle to your face about ten inches in front of your eyes and spread apart your fingers. Closing one eye at a time, view the hand first with one eye, then the other. You'll find that each view is different, that the fingers have different separations depending on which eye you use. Next, open both eyes and see how your perspective changes, how the fingers seem now to be separated by more air, how there is an increased sense of space. This two-eyed form of depth perception is called stereopsis. Those individuals who have a "crossed" or "wall-eye" (strabismus), rather than combining the two views into a three-dimensional percept, typically see one of the views while ignoring the other.

Dr. Susan Barry, a neuroscientist, and the author of FIXING MY GAZE: a Scientist's Journey in Seeing in Three Dimensions was one such individual. Her eye crossed when she was three months old. Three surgeries between ages two and seven cosmetically straightened her eyes, but-as is frequently the case-the surgeries did not restore the brain's ability to combine the information from the two eyes. Sue's doctors, basing their opinions on the science of the day, assured her that she would never develop stereopsis.

The story of "Stereo Sue" regaining her depth perception at age 50 and astonishing the medical community was first told in a 2006 article by Oliver Sacks in a New Yorker. FIXING MY GAZE, however, is far more than a fleshing out the Sacks article. The book is a touching and sometimes lyrical tale of perseverance in overcoming obstacles. It's an excellent resource on Optometric Vision Therapy, the treatment through which Sue regained her vision. It's a wonderful overview of the science and neuroscience underlying the perceived changes. Most importantly, it's the best book ever written about how subjective experience changes during the journey from one-eyed to two-eyed seeing.

The story is completely accessible to nonscientists, the more technical discussions appearing in over fifty pages of endnotes, including copious references. As for who will benefit from or enjoy the book, there are many possible audiences: 1) Those who like well written success stories that also increase their understanding of the world. 2) Those who have ever had strabismus (a condition in which an eye turns in toward the nose or out towards the ear)-whether or not the condition has been "corrected" surgically. 3) The parents of those with strabismus.
4) Those who feel their own vision makes life more difficult. 5) Those with an interest in psychology or the brain. 6) Those doctors, whether ophthalmologists, optometrists or pediatricians, who profess to care for patients with strabismus. And finally (7), those who have pondered the topic of human consciousness: Sue, a neuroscientist, knew practically everything there was to know about stereopsis, but her world and joy of seeing changed profoundly when she experienced stereopsis. To share the excitement and insights of that change, read this outstanding book.

I ordered this new book just after meeting the inspirational Dr. Barry at this year's meeting of the Vision Sciences Society. The book arrived this last Friday and I spent the day reading it. I confess to be blown away by her story, as well as the scientific and clinical implications of her work. Add me to the list of people who loved the book!

Sue Barry's astonishing development of stereopsis at age 48 changed - profoundly - the way that many scientists (me included) view visual development and plasticity. Somehow we had tuned out, en masse, one hundred years of successes using vision therapy (including the extensive the work of Frederick Brock). The stuff of vision therapy was ignored, relegated to the fringes of sensible vision care. Instead, several generations of us took the Nobel Prize winning research of Hubel and Wiesel as gospel truth, going beyond the data by wrongly concluding (perhaps unlike the Nobel laureates) that stereopsis could only develop during a critical period during infancy. It took Barry, a well-established neuroscientist and keen observer, to bring us to our senses.

And yet now, having read her new book, I see that the story is much deeper and profound than I thought. First off, she's a very entertaining storyteller in her own right. The human drama escalated as she went through frightening surgeries as a child (including an encounter with a deceptive anesthesiologist); as she experienced shock and disappointment at being exposed as stereoblind; as she had her vision problems dismissed by one ophthalmologist as a psychiatric disorder; as she experienced steropsis bursting out at her for the first time; as she gained steam and knowledge, recognizing the scientific, clinical, and human implications of her story; as she brought celebrity neuroscientists on board. And so it is a story of empowerment for Barry the patient, Barry the scientist, Barry the teacher, and Barry the instiller of hope.

I believe that Susan Barry has demonstrated for many of us that stereopsis is, indeed, important. I, for instance, was trained to believe that binocular vision and any advantage it afforded us wasn't that big a deal. Sure, I loved stereo viewers and all that... But as an undergrad at Berkeley in the early `80s, I recall a visit by Bela Julesz, of cyclopean vision fame. Two of my academic heroes, Russ and Karen De Valois rose to challenge Julesz, eventually (as I recall) suggesting that two eyes really aren't that much better than one. As I read Barry's book, as well as her descriptions of the consequences of her visual deficit, I realized that my early academic training (as a I had encoded it) was quite wrong. The book makes it clear that lack of stereopsis, and having two eyes that don't fuse images properly, has profound consequences for people like Barry (e.g., her driving, her energy level, and her sense of efficacy). Moreover, it is fair to say that Barry is an extraordinary observer of stereoscopic experience, and that she uses her newfound, developing perceptual ability to achieve scientific and clinical insights that are elusive to us who grew up with normal stereopsis.

One of the epiphanies for me was when I read and grasped the following paragraph: "Just as I could not imagine a world in stereo depth, an individual with normal normal stereopsis cannot experience the worldview of a person who has always lacked steropsis. This may be surprising because you can eliminate clues from stereopsis simply by closing one eye. What's more, many people do not notice a great difference when viewing the world with one eye or two. When a normal binocular viewer closes one eye, however, he or she still uses a lifetime of past visual experiences to re-create the missing stereo information."

People interested in stereopsis will find excellent coverage of the basic issues and the key scientific figures past and present (e.g., Wheatstone, Hering, Helmholtz, Eileen Birch, Shin Shimojo, Denis Levi, Uri Polat, Chris Tyler). It is nice, if not surprising, to learn that the already positive, cool Oliver Sacks played a positive, cool role in Susan Barry's story.

If you have strabismus or some other disorder of binocular vision, you will find what you need here. You will find out how to find an appropriate vision therapist. You will find extensive, understandable information about the theory and science of binocular vision. More importantly, you will learn in marvelous detail about the experiences and practices that can in some instances lead to acquiring stereopsis late in life. My guess is that vision therapy patients will use this book as a guide for years to come.

One last thing: I recommend listening to two NPR interviews (2006, 2009) featuring Sue Barry, as well as other key scientific figures in the story, including Sacks, Hubel, Levi, and, briefly, the heroic Theresa Ruggiero. The NPR programs are available online and go quite well with the book.

Two thumbs up! (one with uncrossed disparity; one with crossed disparity).

My 17 year old son, like Susan had three eye surgeries as a child and he does not have depth perception ("stereoblind"). "Fixing My Gaze" was a real "eye-opener" for me in understanding how he sees his surroundings, his choices in activities (ball toss sports are not his favorite...), and how he manages to determine depth when assembling models, driving, etc.

The book was very well written, easy to read, and has just the right mix of science and personal experiences. Since I could relate to the subject matter it was one of those few books that I didn't want to put down and I read it slowly so that I could savor it!

I can't wait for my son to read it (but it's off limits until he finishes his ACT/SAT tests in a few weeks!)

As a final endorsement, "Fixing My Gaze" is only the second book that I have thought highly enough to send copies to friends.

Thanks Susan!