In the Blink of an Eye
YOU just did it again. Yesterday you did it about 15,000 times. Most likely you were never aware of doing it, but you kept at it and thereby protected two of your most precious possessions. In the process, you may also have offered some unwitting indicators as to how your brain works. How did you do all of this? You blinked.
If your eyes are functional, they are the most delicate and sensitive sensory equipment you have. Widely regarded as a miracle of design, the human eye has been compared to a fully automatic, three-dimensional, self-focusing, continuously filming, full color, motion-picture camera. When not in use, a camera’s delicate lens is covered with a lens cap. But the eye does better than that.
Most of the orb of the eye lies protected within the socket. But the remaining 10 percent of the eye’s surface area is exposed naked to the atmosphere, with all its whirling dust and hazardous debris. To protect the eye against this constant threat of assault, the body is designed with a sophisticated, retractable “lens cap”—the eyelid. Made up of the body’s thinnest skin, reinforced with tiny, fibrous strands, the eyelid slips smoothly down and up over the eye. The blink lasts only about a tenth of a second and occurs some 15 times every minute.
But that tiny, barely noticeable action accomplishes a lot. In snapping shut and then retracting, the eyelid draws a thin film of fluid across the surface of the eye, effectively rinsing it off. It also polishes the eye’s outer surface. So the eyelid might be likened to a combination lens cap, lens cleaner, and lens polisher. Quite a design, isn’t it?
But scientists have long puzzled over an odd point: At the rate that watery tears on the eye’s surface dissolve, one or two blinks per minute should suffice to do the job of rinsing and polishing. Why, then, all the extra blinks? The answer, it seems, is in the mind.
Researchers have drawn connections between blinking and thinking. For instance, anxiety makes you blink more. If you are trying your hand at flying a helicopter, or you are being cross-examined by a hostile lawyer, or you are suffering from an anxiety disorder, you are likely blinking more than usual. If you are a television newscaster, you may have been told not to blink so that your audience doesn’t think you are panic-stricken over the news.
On the other hand, if you are concentrating visually, such as by tracing a line through a maze, driving through city streets, or reading a novel, you blink less frequently. Pilots, for instance, need to concentrate more than copilots, so they blink much less. Blinks are particularly inhibited when a person is in actual danger, and the eyes need to dart quickly from the main field of view to the periphery and back.
There is another connection between brain and blink. According to The Medical Post of Canada, research suggests that “each blink may occur at the crucial instant in which we stop seeing and start thinking.” For example, a person memorizing something will probably blink right after scanning the information he wants to store. Or in decision making, tests suggest that “the brain orders a blink when it has enough information to make a good decision,” notes the Post, adding: “Experiments indicate that blinking serves as a kind of mental punctuation.”
It was nearly three thousand years ago that a wise man was inspired to write: “In a fear-inspiring way I am wonderfully made.” (Psalm 139:14) The advances of medical science in our day have only bolstered that viewpoint. Just imagine: polishing and lubricating a sophisticated lens, registering the degree of the brain’s concentration or anxiety, and punctuating the inflow of visual information—all of that in the blink of an eye!
[Picture on page 14]
Orb of the eye with only 10 percent exposed