The Mind's Eye

Dr. Oliver Sacks, author of The Mind's Eye, turns his considerable writing talent inward in this true tale of six patients, including himself, that shows just how much the brain adds or subtracts from the "visual" interpretation of the world surrounding us.

For Dr. Sacks, a tumor caused him to lose the ability to recognize the faces of even his loved ones or himself, eventually it clears up, however the interesting issue is that during the time he loses not only his ability to see those around him or recognize them, he is able to see with normal depth of field. It's interesting to note, the witty and skilled writer shows that the brain will fill in the holes that our visual field leaves.

If you think about it, it does makes sense, as well, since this points out just how much of our world we perceive and make sense out of by a combination of the brain and eyesight. As an example, you have the newborn who, though unable to verbalize what he or she is seeing, is constantly looking around and soaking the world around like a sponge so that when it comes time to communicate, the child can easily talk about what he is or isn't seeing.

Dr. Sacks, a famed neuro-ophthalmologist, also plunges into the sensitive field of 3D or standard vision, pointing to patients who, having lost a good deal of their sight, still report "seeing" things around them, such as the chairs they know or the rooms that are familiar with. No, we wouldn't particularly want to drive with a person who might be three-quarters blind, in reality, yet the amazing amount of detail that they can give about the world around them, shows you exactly just how the brain uses the stimulation it has accumulated over the years to make things work.

Indeed, Dr. Sacks, indicates that those whose eyesight is often the worst, but who report "seeing" chairs and desks, as well as a roomful of furniture "where is should be" also shows how much your brain and eyes interact.

Believe it or not, all of this happens within five degrees of room enhancing "depth of field," or binocular vision. To prove it, look at some of the dual-lens cameras on the market and you'll see that the each eye image overlaps enough so that there is not only a true image from the eye, but there's enough overlap from the other lens image that you will receive the 3D image.

Dr. Sacks isn't afraid to use his own illness as one of the five examples, and then there's his patient who ends up loses nearly 75 percent of his vision and yet who reports to the doctor that he still "sees" full rooms around him, though it is impossible. Again, as Dr. Sacks skillfully proposes and achieves, the brain is probably your body's most powerful "filter." The patient who reported this to the skilled researcher and surgeon, Dr. Sacks notes, did so out of fear that people think he was getting some form of dementia. Yet, as we have seen, the eye/brain combination effectively fills in the information that is missing from the application (eyesight, here, for example).

Or, how about the author who lost the ability to see what he was writing so in order to meet deadlines he writes whole scenes and chapters in a handwriting that he doesn't even recognize as his own.

Many of Dr. Sacks' patients regain their ability to see in "real-time 3D" - normally - but they may also report enhanced sensual inputs as well as it has been reported that those who were blind but who can see again - for whatever reason - often find that they hear more than most, which can be disconcerting.

Finally, there's the patient who, though blind, uses his many years in a neighborhood to populate it with the parks, benches, drink fountains and markets, and he can actually walk around his neighborhood, reports seeing his neighborhood as he walks through without an aid or dog. It's an amazing story, but one that, from personal experience, we know to be true as we have had some visual nerve damage thanks to a tumor and our brain has filled things in normally for 30 years.

Dr. Sacks' journalistic and perceptive writing on a subject he clearly knows makes this another must-read when you have the chance.