Cutting Room of the Mind

The Face: A Natural History
By Daniel McNeill

(Page 6 of 12)

Even the busiest attorney or executive loses about twenty-three minutes in every waking day. They simply vanish and we are oblivious to it, as if spellbound. The time trickles away in 14,000 tiny gaps, which the brain edits out of our perception. They are blinks.

Blinks are like the spy who lived next door. They seem utterly ordinary yet hold many secrets.

They recall our aquatic origin. When the first tetrapods crept onto land some 370 to 360 million years ago, they faced the peril of desiccation. In water, animals never dried out; on land, the sun stole their very substance. Early amphibians slipped in and out of water often and reptiles evolved near-watertight scales. But eyes contact air directly, so to keep them wet, creatures developed eyelids with tear glands. Each blink is a little dunk in the primeval sea.

The eyelid is the tool of the blink. Cicero called it "exquisitely designed by nature," and he could not have been more correct. For instance, the eyelid blocks out the world when we want to sleep. But since it is just one millimeter deep, the thinnest skin on the body, it is slightly translucent, so sunrise or sudden light can wake us up. The eyelid helps register alarms.

Above the outer corner of the eyelid lurk the tear glands, which emit a fluid that the lids sweep over the eyeball. These tears are not just water. They are part of the circulatory system. The cornea must be transparent so we can see through it, and hence it has no blood vessels. Tears bear oxygen to it and keep it alive. They also contain chemicals that kill bacteria and proteins that smooth the eye surface and trap debris. A quarter of tear fluid evaporates, and the rest seeps down into the nasal passages and keeps them moist. That's why crying makes us sniffle.

Eyelashes highlight the blink. They are a moving palisade, holding insects and other hazards at bay, and indeed blinking is a reflex to any threat to the eye. The lashes perform the same task as the hairs in the nose and ears, but they live in Elysium compared to their troglodyte cousins. They are the eyes' attendant graces. Emma Bovary's brilliant brown eyes, "her real beauty," seem black because of her lashes. The starburst pattern of lashes draws attention to the eye, and flirts flutter them to gain even more. Eyelashes are erotic in other ways. In Remembrance of Things Past, the narrator and Albertine entwine eyelashes in bed. Malinowski says Trobriand Islanders bit off eyelashes in lovemaking, an act they called mitakuku.

We say "in the blink of an eye" to mean "instantly," but objectively the comparison falters. The average blink lasts a third of a second, and the lid covers the pupil for a sixth of a second, during which we are blind. (Deliberate blinks take longer and no one knows why.) This gap is far from an instant, since we can detect flickers as brief as 1/300th second in a lantern. In fact, a sixth of a second is long enough for an attacker to catch us off guard, and biologists like George Williams have wondered why we always blink both eyes at once. If we alternated blinks, we could see the world all the time.

On the other hand, subjectively the comparison is almost too good. Since the brain kills awareness of normal blinks and knits the world into one flowing vision, a blink seems to take no time at all. It feels shorter than an instant.

Blinking is like breathing. We do it automatically, all day long, about 15 times a minute. Dry spots begin to pepper the eyeball after 15 to 45 blinkless seconds. Slow-motion photography reveals the career of a blink. The lids shut like a zipper, traveling inward from the outer edge to spread the tear fluid. They close twice as fast as they reopen, like a coquette turning her head and slowly looking back. Surprisingly, we rarely complete a blink, unless we're blinking deliberately. It doesn't seem to matter.

Pliny the Elder says that of the 20,000 gladiators in Caligula's training school, only two did not blink when facing a threat. They were thus unbeatable. In folklore, the blink has long suggested broken concentration. Whoever "blinks first" has lost focus and nerve. We say "without batting an eye" to mean "apparently unperturbed," and a "blinkard" is a dimwit.

Science supports the folklore, in essence. When we look or even listen intently, our eyes stay open, as if to suck in every mote of information. But when our attention strays, we blink. We blink less while we're reading sentences, and in bursts in between. One experimenter found that his best readers kept their eyes open for an entire page, and released a flurry of blinks when turning it. Drivers blink as they turn to glance at the speedometer, and again after they've assessed the velocity. We blink less when tracking an object or working a maze and more just afterward.

On the other hand, as we grow bored or fatigued, we blink more. If we drive a car or read for a long period, the blink rate rises. In one study, people were blinking 6.9 times per minute when they started reading and 11.0 times per minute four hours later. As concentration wavers, the eyelids dance.

Speaking also boosts the blink rate. For instance, doing mental arithmetic doesn't change it, but if one verbalizes the steps, it jumps. Reciting the alphabet silently slows the rate; reciting it aloud quickens it. We blink less often while listening to a question and formulating an answer, and more while delivering it. Blink frequency also rises during cross-examination on the witness stand, or even just talking with a friend. We may blink more when speaking because we are absorbing less information or, some scientists think, simply because we are moving the tongue.

John Huston likened blinks to cuts in movies, since we blink when shifting our gaze from one spot to another. Walter Murch, editor of such films as Apocalypse Now and The English Patient, goes further. Natural blinks can almost dictate cuts, he says. Where a careful listener blinks, a film editor can probably cut. Skilled actors also blink at good cut points. Blinks help us make sense of a continuous world by dividing it into little chapters, he feels, and ultimately, the film editor is blinking for the audience, cuing it to discrete thoughts or acts.

Blinks communicate. Actor Michael Caine eschews blinks in close-ups, believing they lessen intensity, and for years actually practiced not blinking. Murch suggests that blinks show others when we have grasped an idea and thus subtly coordinate conversation. Bad actors, he notes, don't think their characters' thoughts and so blink at the wrong moments. So do politicians. Such miscues disturb the rhythm and we pick them up, he says. We sense unnaturalness and often assume such people are lying. He may be right. Blink science remains in its nonage.

© 1998 by Daniel McNeill

About the Author

Daniel McNeill is a bestselling author and winner of the Los Angeles Times Book Prize for The Face. Mr. McNeill is the principal author of Fuzzy Logic, which won the 1992-93 Los Angeles Times Book Prize for Science and Technology. He has written numerous other books and articles on high technology, and his work has also appeared in fiction, travel, history, law, and education publications. He lives in Southern California.