This is a serialization from my book, Happiness: A Physician/Biologist Looks at Life. To see the Table of Contents and the dust jacket blurb, click here; to start from the beginning, click here; to read the previous post, click here.
The Normal Blind Spot
Let us return to vision, to make a few more points. In vision, there is yet another illusion that is a constant problem, but one of which most people are totally unaware. You can demonstrate it for yourself.
Look at some horizontal line, say the top edge of a door or a picture frame. Close your left eye with your left hand. Hold up your right index finger at arm’s length, so that the fingertip blocks the point you are looking at. Now, move your finger very slowly to the right along the horizontal line, without allowing your eye to follow it; keep your right eye focused on the place were the fingertip was. When your fingertip has traveled about 4 inches to the right, it will disappear. If you continue moving it, it will then reappear.
Your fingertip won’t disappear in a “poof.” In fact, where the tip of your finger “was” you will simply experience—or think you experience—some continuation of the scene in front of you. But you will be quite aware that the fingertip is now gone, and in fact, that you see nothing at all in that small area.
It is, quite literally, a blind spot. The anatomical explanation for the spot is that it corresponds to the area where the visual nerves all exit the eye, and displace normal vision cells off to the sides. For our purposes here, however, it’s an area of blindness that we constantly experience, without any idea that it is there.
There is a similar problem that is less common. Some patients lose their vision gradually, with a slow, constricting blindness. It’s called tunnel vision. Patients who lose their vision in this way are generally unaware that they see less than they previously did, or that they don’t see what everyone else does.
Blind spots and tunnel vision: these are both metaphors for how we approach life. It is not unusual for us to think that our vision is complete, when it really isn’t. We are absolutely sure that the blindness is not there, that our view of something is complete.
It’s even worse than that, however. Not only are we blind; not only are we blind to the blindnesses; but often we also insist that the blindness does not exist at all. It is not unusual to inform a patient that he has lost some of his vision, only to have him insist that the doctor is wrong. He will reject the information, and adamantly insist that there is nothing wrong with his sight. Even with a demonstration, a “proof” of the problem, he still insists that he sees normally.
The Holes in Our Vision
So, not only are we saddled with deceptive holes in our vision, but we are also saddled with a predisposition for illogic. We do not want to see that we cannot see perfectly.
This does not only happen with vision. I have seen so much sadness, so much tragedy, with people who cannot see that they cannot see, but insist that they can. Recently anorexia nervosa has emerged in the popular literature, a disease where people will starve themselves to death, insisting on their death beds that they are obese. Medicine—and therefore life—is full of such tragedies: the mother who demands that her child is not brain dead; the patient who ignores the cancer that is eating away his face; the stroke patient with severe one-sided paralysis, who is positive that he is perfectly healthy.
“There is none so blind as he who will not see.”
Sooner or later, this is all of us.
To continue reading, click here.
‘Boy with Flowers’ courtesy of Adina Voicu on Pixabay.