Vision Health and the Computer: Dry Eyes Burning, Screen Unreality, and Depth Perception Flattening

Computers hurt our eyes. We hold back from blinking while staring at computer screens and televisions. It’s from the way we work. And it’s from what computers show us.

We’ve been here for millions of years. We know the natural world. We judge by natural-world standards. But those standards don’t apply to computers. Computers make a mess of our lives.

Something vital can change in an instant. That’s one key. In nature, some things change so slowly we don’t notice, some things change noticeably but still slowly, some things change quickly but don’t much matter, and a few things change quickly and are critical.

But computer change is hardly natural. Knowing of every change may be vital to our surviving. A quick change, even if subtle, can be finished within a fraction of a second. A blink can last as long as that fraction of a second.

Our own eyelids may be guilty of hiding a change impacting survival. We can’t afford to blink, but we can’t stop it, either. Our fix: We try to withhold blinks, which means we tend to blink far less often and then try to figure out what we may have missed anyway. This need for constant visual alertness likely hasn’t changed since lions stalked the valleys outside our ancestors’ caves. We may need sensitivity to each other, person to person. Someone who’s crucially important to our family or professional life may give away unspoken cues. So, too, with sexual attraction. If we try to catch those cues and they’re subtle, we have to search the surface to pick up variations. If a twitch might be meaningful, we don’t want to miss it. So we look for rapid subtleties in both cooperative relationships and competitive contests. This applies to fights, sports, million-dollar negotiations, and war-and-peace diplomacy. In a fast-unfurling situation, blinking denies the brain information it needs. When we’re face to face and it’s vital, we don’t take a chance on missing a thing. We don’t dare blink.

Other keys are unnatural graphics and human depth peception. They’re coming up.

Personal Experience

Lyin’ Eyes

After working nonstop except for bathroom breaks for six to seven hours at my laptop and then walking outside in sunlight for up to half an hour or so, I found it difficult to focus my sight. My laptop reduced the need for depth perception, so that I temporarily lost most of it. Going outside challenged my vision to regain depth-of-field perception. While I could function and walk without bumping anything, and my vision was back to my normal by the time I was on a subway and reading a book, still maybe operating a machine could be dangerous. Like maybe it’s good I was not driving a truck.

The length of time for my vision to recover may be related to how tired I am. Back then, I often functioned on little sleep each night. I don’t know if this happened on the same nights, but it likely did. I sleep more each night now, approaching a normal length, and my eyesight recovers in just a few minutes, even when I’m using a computer in a dimly-lit room. Nonetheless, there is still a recovery period, long enough to notice.

It’s Gone. Gone!

A slip of a fingernail and all our best work vanishes. In olden days, we’d need a rubber eraser or white liquid. You had to reach around your real physical desk to get the thing that would make your mistake go away, stop typing, do what you had to do, and then get it right. Now, it’s just a finger tap. What used to take a moment now takes a split second. You don’t even remember the tap. Your beautifully crafted prose is gone.

When the accidental overdeletion gets devastating is when we’ve gotten more confident and then we’re sure we’re only deleting a comma but we delete our best chapter, the whole beautiful thing off to the sea, drowning without even waving at us. We type a tad more before we realize what happened, maybe making the Undo option useless. Horrified, we scream, or cry, or offer a bribe to the computer, or dial the Mafia, anything to make the slimy silent type give us back our perfect prose it swallowed.

Nothing doing. You’re not getting it back. You’re now a bundle of nerves ready for full leather restraints in a padded room, and the next time you type you plan to have a knife between your teeth, just in case your computer tries to get smart with you again.

And it will. Your computer multitasks. That means it might do its own thing while you just try to work.

You type a sentence. You’re looking at paper. You glance up and discover a warning message about who knows what. Most of what you typed never arrived.

Worse: At the end of a paragraph you hit the Return key. You didn’t see the warning message waiting for you to hit the OK button. The Return key took care of it for you. You never saw the warning. Now the computer is doing strange things and turning your world upside down.

You’ve absorbed an annoying lesson: Always stare at the computer like it’s wrestling you on national TV. Computers inspire fear. They delete faster than a toddler can grab an electric plug. We calm down eventually, but never completely.

Really Happened to Me

Clicks in a Clique

Here’s what happened one night. It could have been a dark and stormy night, but I wouldn’t have noticed.

In a database, I had to go through many records and determine the state of one field in each record. The layout showed one record at a time.

I placed the mouse cursor over the button that would bring the next record into view with each click. I was ready to tap-dance like a rabbit.

I stared at that one critical field. Without moving the mouse, I vibrated my fingertip: Cli-cli-cli-cli-cli-cli-cli-click.

When I flew past the rare record that needed work, I’d just go back and deal with it. Then I’d resume my bad Morse code.

When screen redraws seemed to have difficulty keeping up, I slowed down, albeit not by much. I didn’t care whether an image matched the official record number, as long as I saw all the records. Occasionally, I double-checked back, and all seemed well. And I had a thousand or so records to check. Onward, I drummed.

But I hesitated to blink. I became conscious of hesitating. I became concerned about possible ill effects. Doctors are expensive. Yet, I was worried that a record would fly by and I’d never fix it, and I wouldn’t have fulfilled my responsibility. And we all know that when you have to get your day’s work done, a lifetime of blindness is a small price to pay. So I worked on.

How much time I gained by not blinking was maybe one to ten percent. That’s major. Don’t tell your boss.

I didn’t think about those numbers. Instead, I kept my eyelids parked high in my skull. Then, I began to reflect. Maybe this is a mistake. I changed my mind. I clicked slower. Click; and click; and click; and click; and click.

This compromise allowed me to blink without missing a record. I could even blink at a healthy, normal rate without missing a beat. I didn’t work quite as zippily. I still got the work done, mainly because I was working overnight alone and no one was expecting results till they walked in the door in the morning. But I wasn’t happy to slow down.

I probably could have redesigned the database. However, not all users are permitted to design. We may have to live with what’s already installed. Bosses can make that perfectly clear.

200 in 45

At another time, I did a test. I clicked through, and displayed, 200 records in one pass in under 45 seconds. I don’t know if I blinked during the display, but in 45 seconds I should have and if I did I would have missed at least one record during each blink and may have had less than the average time to see the adjacent records before and after each missed record.

The same result was achieved on a second pass: under 45 seconds for 200 records. The only difference was that I navigated backwards for the entire process, rather than forward.

If it had not been a test but a real search through such a database, I might have had a different result, for two reasons: The 45 seconds included time for switching twice between the Approach window and Date/Time Properties. On the other hand, I would have been slowed by a need to see each record; looking away would have required compensatory searching, e.g., navigating backwards for a few records to be sure of having seen every record. However, the latter would have slowed only the average time, not usually the viewing speed for any two adjacent records.

To a scientist, this is not much better than anecdotal evidence. Sampling the human population for a lower margin of error would be more reliable and is possible and, with blinking, scientifically ethical. And anecdotes may inspire scientists. They can design a test suitable for peer review. But when the available reports are the best we’ve got so far, and our health is at stake, we’d better take advantage of what we know. Historically, it saved our health.

Coming to our Eyes

Depth or Not

In nature, we find what’s intimately close and what’s so greatly far we experience parallax. We know distance because we have depth perception, and we have that because our eyes change angles and our brain compares the two images to estimate distances.

Computers are not like that. Computer screens are relatively flat. We see a picture of a river and the moon and they’re both about a foot and a half from us. Everything looks equally near. Our brain no longer needs depth perception. Our eyes have less need to coordinate their motions. Our brains have less reason to make them coordinate. So, we lose it. Our eyes lose focus for any distance much more than a foot and a half.

Case: I worked under two hours on my laptop, walked out in daylight, and then almost didn’t see a step going down.

When we look away, and we will, adjusting for depth relieves us but also the need to re-adapt to the real world disturbs us. We remember that disturbance the next time we have to stare at a computer. The effect is starkest when the real-world light is bright or when we need to see far sharply or differentiate distances without thinking.

Books also have pictures of rivers and the moon. But we look away much more often than when we’re glued to a computer. Just flipping pages is enough to exercise our depth perception.

Computer Content Jarring Brains

It Really is the Computer’s Fault

The content is part of why we hold back.

Computers are new. Graphical user interfaces are even newer. The graphics are chronically unnatural. While smart designers struggled and the pictures are colorful and sophisticated, they can’t be perfect. They’re just wrong enough to disturb most of us a little, daily. They snap and crack past our eyes. And they’re weird: You have a window inside your desktop. What furniture store sells a desk with a window in it? And a mouse opens a window. Right. The screen flashes with new things suddenly disappearing. Messages fade. What did it say? That stirs an undercurrent of stress for hours, keeping our eyes open like saucers, adding physical stress to the mental.

People on the autism spectrum might have more difficulty in recognizing the graphics as metaphorical. And some autistics are highly educated and highly placed in careers and highly functional.

If you eat paranoia for breakfast, you may know that even a still photo might move. If it does, that might have a meaning that no one told you. That can include splash screens and desktop patterns, which can be shown serially. I had one. It was from Microsoft. You’re stuck fuming.

You can’t study enough about a computer to grant yourself superior expertise. Top Geek Number One, with a cape, can’t know enough. Every major computer product has mysteries waiting to snap your nose off. Some are Easter eggs, often fun, like a rabbit crossing a page. Microsoft didn’t know it had a flight simulator buried in a spreadsheet program till they got thank-you letters, and that company has plenty of geeks inside its doors. Other mysteries include potentially useful features the producer changed its mind about, and didn’t publicly document. Help files usually won’t acknowledge that undocumented features even exist. If a pile of geeks can’t keep up, it’s hopeless for you.

We cope, but coping doesn’t make us comfortable. It only means we’ve down-shifted our attitudes to tolerate the way things are. We’ve agreed to stop boring our coworkers in breaks. They have the same problem, they can’t fix it, they’ve shrugged their shoulders, and they’d rather talk about something else, but we’re often still uncomfortable. And we don’t blink. Staring with a fear of blinking has gone on since we first learned how to use a computer. We’re experienced with the machines and yet they instill a bit of fear.

Against Nature Itself

What’s “natural” is not limited to what humans had nothing to do with creating. To be technical here, humans are part of nature, so, in a sense, everything humans create is part of nature. However, we often speak of natural as excluding what humans invented in modern centuries. For very good reason, we don’t consider hydrogen bombs natural. Nor are nylon shirts and soda pop taken as natural. When we popularly judge what’s natural, we look to the anciently familiar, especially the prehistoric and the prehuman. That’s what’s natural to us.

Visuals are more natural than words. Popular writers usually conjure word-images readers tie to their senses. Abstractions are shunned when colors, smells, shapes, touches, temperatures, saltiness, sniffles, gusts, and thunderstorms can be invoked directly. We learned how to communicate through visual imagery years before we learned to talk. That’s why computer designers came up with desktops, icons, windows, buttons, 3-D, color, draggings, droppings, motion trailings, customizability, and other analogues to the real world. These designs work well in introducing computers to many of us, and introducing them faster.

Still, we know computer imagery is all “pseudo,” every last bit of it. It’s not natural. Microsoft sprung an obnoxious dancing paper clip on screen that criticized our work. We’re on guard. We understand the real world, yet we don’t quite understand the computer world of make-believe. We’re not quite sure what’s going to change without warning, and change vitally. In real life, wispy clouds in the distance can move miles, and still they’re nice and timid. But if any clouds in a computer background move an inch, we have to worry.

We look forward. We try to predict what will come next and what it will mean. Predicting the very near future is part of human survival. But computers make prediction difficult. To understand how computers foretell, you have to be a nerd. If you don’t know if a nine-bit byte contains a nibble, you’re probably a human. You and computers likely suffer a culture clash. You have to eyeball it like it’s a rat that needs to starve.

There’s always a few among us who find the common computer graphics entirely natural. Most other users call them “geeks,” “weird,” and people who should “get a life.” So far, most publishers, corporate directors, prime ministers, artists, union officers, parents, and religious leaders are people who may know how to use a computer but are not deeply into them. Politics, faith, expression, children, and economics are natural to them; base-two counting is deficient and retarded, making anyone who thinks otherwise bizarre and alien. True, these oddballs make helpful things happen, so we don’t question their births too closely where they can hear us. (I confide in a few people that I was born at canal no. 7, got bored, and went to Earth. Some people refuse to quite believe that, but that may not be unanimous.)

Unnatural it may be, but you’re stuck with it.

Your Rattled Perspective

Your brain lies to you in order to reveal a deeper truth to you.

You stand in a street and look at a typical building that’s several stories tall. You’re sure it’s rectangular, and the architect, the builder, the owner, most occupants, and most passersby would all agree. Then you take a photograph, and it shows up as a trapezoid against the rectangular sides of the photo print or the slide mount: a bit like a flat-topped pyramid. Why pyramidal? It’s because where you stood the top of the building was farther away from you than the base was, and distance made the top look smaller. The base looked bigger. Most cameras catch that perspective. Yet, when you look with plain eyes, your brain, which is Nobel quality, knows perfectly well that the building front is just as wide at the top as at the bottom, and adjusts the mental image even while you’re glancing or staring. The camera is too stupid to adapt. Your brain is smart and human.

In computers, perspective can change in ways that defy the hard laws of physics. In real life, you can blink while staring at a building because you know it isn’t going to change much in half a second. We understand buildings. But computers? First they amuse us by doing amusing things with grahics. For one, perspective gets distorted. It’s cute. But then we discover that a computer might twist perspective any time it wants. We can’t stop it. Maybe we go mad. We watch with eagle eyes. Ever see an eagle blink? Didn’t think so.

Disappeared Text

New users soon get trapped. One of the first major applications they learn is probably a word processor. Mouse neophytes select text, hit the Delete key, and Wha-a-at! what we wanted to hold is gone and how do we get it back?

Mousing is a skill, and maybe a newbie thinks if one click’s good three are insurance. When you hold a pencil, do you worry about the pencil’s left or right side? Pencils are user-friendly. So were crayons, which you’ve been using since you were, oh, about two years old.

Now the new student moves the mouse to select a word. Only a very slight movement, just a pixel little, is enough to select the wrong sentence instead of the word. This is new to people who are used to typewriters or handwriting. Touch typists used to be trained to not even look at the output, just at the original paper. But that’s no longer acceptable. Typewriters of old, once they were typed on, couldn’t change what was on the paper. If you used white-out on a word, the rest of the paragraph stayed proudly black. No longer. If the computer is friendly, there should be no need to look at the screen. The first time, every user looks. But, with slight experience, the new user stops looking. The screen should reflect exactly what the user intended, since no one else came in between. Without looking, the user taps Delete. The wrong text flees to Pluto. Thus, the lessons: The computer is a rascal. Computers are unpredictable. And, human beings who use computers have to be strange in the brain.

So, we become alert, to catch the evil computer, before it plunges the planet into darkness. One fault makes us nervous that another shoe is about to fall. If too many fall in a minute, we lose count and lose control. The computer controls us. Fear roils us. We fight back. We’re not going to let it get away with anything again. And yet we never quite let go of that fear, which becomes a fear of blinking. For good reason, because computers will still catch you unaware. If one problem happens, we fear another right around the corner. If your computer has anything you need, you’d better watch it.

You can think, simply think, you’ll miss something. Just thinking it is enough to persuade you to delay blinking. You’d hold off all day, if you could. Eventually you’ll blink, but your eyes will dry out first. The harm begins.

TV and Film

Movies normally run at 24 frames per second (fps). I think there’s no gap in between you’d ever notice. A television image lasts for one-sixtieth of a second, which I think is actually represented by 30 images a second with blackouts sweeping in between. One blink means you miss a few frames. But those media are less demanding of visual continuity, because they’re generally not interactive and their content is designed for passive absorption. So, you’ll miss something, but the main consequence is social. You’ll be alone at the water cooler, but you probably won’t get fired. And you probably won’t be alone at the water cooler anyway, because everyone else watching had to blink at some other interesting moment and you can tell them about that one, and they won’t even ask.

Computers are different. Even streaming videos made just for computers can be different.

Sneaky Print

In ordinary work that’s been around for hundreds of years, like reading paper text, we time our blinks to reduce interference with vital work: according to a teacher of intellectual history (not of health), “we almost always blink when we see the period at the end of a sentence. (Watch someone when they’re reading and you’ll see it.) Yet this is an entirely learned response.

Physical Consequences


Without blinking, our eyes hurt. Our pain comes as burning eyes. Or as a headache. Our eyes dry out. So our eyes start to feel like they’re burning. Our necks hurt. Our headaches distract us.

We want to hurl a brick at the computer. We’d get fired for that. So, we burn inside and keep working, until our eyes burn from staring at every dot. Dots by the millions. Literally, millions. We wonder if our bosses really have such great personalities that we want to do this. Then we remember our housing and grocery bills and we type some more. And we stare at the picture. We have a job to do. Can’t lose the paycheck. Can’t miss what’s on the screen. So we don’t blink. Momentarily not blinking is harmless, and what we gain by glaring may more than make up for it, but doing it for long reverses the odds.

Till we take a break, and, we hope, go outside. That’s when our eyesight has to adjust itself to the real world. Focus is a little off. Far and near are different, after all. Daylight’s bright. Things look washed out, maybe slightly faded, which makes no sense. It takes a while to catch up.

You have it worse. You have to stare at that computer all day. Databases and long memos are not the only culprits (and you probably didn’t think they were). The operating system may be no better. Messages can go by so fast they couldn’t be read by any human alive. Even something that does not change much can be threatening, if it engages you. Engaging you means causing many thoughts. That’s like change. The change can be in the meaning of what you see. If you’re reading a text and you’re deeply absorbed in it, maybe meanings can be intense and fluctuate every sentence or so. Here’s one case, from an optometrist (a doctor) in : “About a year ago a woman came to me who complained about having trouble reading because her eyes burned. But she was having trouble only while she was reading at work. She was a lawyer. If she read a novel, she didn’t have any problem, but when reading a law brief, her eyes would burn and burn after about ten minutes. . . .

It turned out that whenever she read for her work, she would forget to blink. She would become so engrossed in what she was reading that she would subconsciously suppress the urge to blink, so her eyes would dry out and burn! As odd as it sounds, many people become so involved in what they are doing that they simply stare at their work. This is especially true for people working with computers, since this type of work demands extra concentration. The normal rate of blinking is about once every five seconds, but with intense staring, the rate can easily become once every minute or two. This will dry out your eyes and make them burn. . . .” Dr. R. Anthony Hutchinson said so.

Contacts Popping Out

Contact lenses, too, make a problem. “You have to blink when you wear contact lenses. Blinking properly coats the lenses with tears and keeps them wetted. It also pumps fresh tears under the lenses. If you don’t blink enough or don’t blink your eyes completely closed, the lenses will dry out and become uncomfortable. They may even pop out. A friend and patient of mine told me that the only time one of his soft lenses ever came out of his eye was when he was staring at his computer screen. He was staring and concentrating so hard that when he finally blinked, his dried-up soft lens popped out. Since he is now conscious of his need to blink when working with his computer, this hasn’t happened again.” So said Dr. Hutchinson.

Slowing with Age

If our reflexes are slower, difficulties are greater. Usually, older people have slower reflexes. Often, though, the slowness is not an impairment. It’s because they’re conscious of more interconnections across their world and therefore hesitate to act in ways that might incur liabilities they know they should anticipate, some of which liabilities are of less concern to younger people seeing opportunities. To older users, computers’ graphical user interfaces (GUIs) imply interconnections that likely seem harder to expect to resolve, and thus lead to more hesitation or workarounds. What may seem fine in a GUI to geeks may be troublesome to ordinary people and especially to traditional people who are not geeks. In particular, the unnaturalness of the GUI is often even more disturbing to people whose many life experiences make it harder to fool them. GUIs generally depend on fooling us, which is why it’s easier to teach children how to use computers than it is to teach adults the same skills. Motivational differences also abound; adults who don’t have much need for a computer are less amenable to the subject, whereas children are more interested in new potentials and powers and may at any rate be bored with other subjects in school and glad to have a distraction with interaction. Telling a quite-grown adult that the thing is a “window” is to be arbitrary when that is harder to accept, while younger people accept it more easily. When we depend on matters making sense within a complex world, it can be harder to adapt to a GUI. If the user has to worry about changes in the computer, a GUI that’s harder to believe can get on the user’s nerves. If the user is engaged in the work nonetheless, the user’s eyes may be especially engaged, and the blinking slowed. Better GUI design is critical to reducing the degree of specialization required to qualify as a user, and thereby to growing the number of people who will readily use the machine and get more done.

I’m Leaving Out Radiation and Fluorescence

This is not about radiation. That was more about older computers anyway, with their CRT monitors that looked like pyramids that fell over. Now we have hip and cool thin monitors that don’t radiate as much or at all. Or they’re not hip and cool but they still don’t radiate as much or at all. And radiation makes a different problem, not this.

Maybe the rapid flickering of fluorescence and that of computer screens interact on people’s visual systems. I don’t know. I won’t cover that here, but maybe someone else has, or will. And computer redesign likely can’t help with fluorescent tubes and ballasts anyway. I’ll deal here with what’s on the screen and your vision.

Why We Must

Eyes Get a Bath 24x7

We blink because we physically have to. Blinking soaks our eyeballs in front, so they won’t dry out, get injured, and feel like they’re burning. How often we blink is largely determined by our eyes’ need for protection.

No one can be on maximum alert, on edge, all the time, not even a trained and driven military combatant in a raging war. We will return to medium and low intensities most of the time, even if our environment is lethal to us. The same is true for our eyes.


The core of a blink is the darkness time, the time while the eyelid blocks the opening you see through (that’s the pupil) and is giving you the closest thing to a blackout. (The eyelid is not made of lead and can let very bright light through, but the light that gets through is so dim and diffuse as to give you almost no information.) The eyelid staying down and stationary should be brief and can be. It only needs to replenish fluid. It can then return. Thus, the eyelid can practically bounce. The first part of the darkness time may still be painted by signal retention in the activated visual nerves in the retina, reinforcing what was seen. As reported in , the whole darkness time averages one tenth to four tenths of a second.

Before and after, in my observation, the eyeball itself turns. While the lid is dropping, the eyeball rotates downward, too. When the eyelid rises back up, the eye rolls back up, too. (I wear glasses, and, if I pay attention, I see a slight rising of the frame’s top relative to a stationary high-contrast background when I start a blink.) I don’t know if rotation starts before the lids start downward or continues recentering after the lids finish traveling up, but those times have to be included, too, in vision impairment time. (I assume that in healthy people both eyelids move simultaneously and in the same amounts and so do the eyeballs.) (Re-rotation may not be unrotation if any parts of the rotation and re-rotation of either eye are not inversely equal.) There’s also an inward movement, which, being simultaneous with downward, won’t matter here. I don’t know what doctors call that whole motion before and after the blink, so I’ll call it the near-blink indirection time.

The near-blink indirection time is perhaps equal to the darkness time. During most of that time, because the eyeball rotations redirect the pupil away from the object, your eyes are not looking directly at your object. The object you saw becomes part of your peripheral vision. When you’re not looking directly at your object, you tend to misperceive and misremember it. (You might refer to this as “looking out of the corner of your eye” and we often associate errors in perception with having relied on that peripheral vision. To rely on it takes practice we don’t usually have.) That kind of error is one that your brain likely tries to correct for by recalling what it saw during object-centering before the blink began, but that prevents your brain from updating visual knowledge, thus effectively reinforcing that you are not accepting retinal updates during the pre- and post-blink times.

As a little experiment, try blinking a dozen times as fast as you can while looking at fast-changing scenery. You probably have difficulty understanding what you are seeing between the blinks, relying instead on what you recall just before you began your series of blinks.

This assumption that what you saw a split-second earlier is what you would still be seeing except for your blink fools almost everyone for the sake of a larger truth. This deception works even if you’re a widely-published top professor and research scientist with a Nobel prize under your belt or a devoutly religious minister or a parent of a baby who looks up to you or the pilot of a plane. Even if you study vision and are aware of this, you probably can’t be aware of it all the time, because defeating the compensation could be more dangerous to your survival than it would be worth. It would be like thinking of every muscle and bone involved in taking a step; you’d soon abandon walking even at home. This fooling is a livable compensation, provided things don’t change too rapidly, but sometimes they do.

Altogether, the complete blink and decentering is thus about half a second. Doubling the blink (0.1–0.4 of a second) gives us 0.2–0.8 of a second and the middle value of that is half a second.

In half a second, things change. Dangerous things, too. “Better watch out” is meant literally.

Fatigue in your body may lengthen blinks. Your brain would rather your eyes just stayed closed. If you resist, you might later do microsleeps. One microsleep, which is less than a second, is enough to smash a truck driver who unwittingly drifts into the wrong lane. You’ll fight the drowsiness, but the compromise may just be a slower blink, maybe even a few seconds long. You’ll miss stuff. Flowers may be sent to the funeral home.

Your brain, being intelligent, compensates for predictable errors. It does it continuously. You have a blind spot in each eye, because of the layout of retinal nerves. However, you don’t notice it in the scenery, because your eyes scan, making up for the blind spots. Your eye scans should produce a flicker in what you see, but they don’t. Your brain compensates so well for the flicker and the blind spots you don’t even notice. It compensates for movements of your eyes. It compensates for blinks. That’s how you can think you’ve been looking at something for hours as if you hadn’t blinked. You just don’t think of it.

Blink rates have been measured for ordinary use and in front of computers, although different exams don’t entirely agree. One measurement or statement was every four seconds without a computer or every 8–12 seconds with one, then one was five and twelve, then another was four and more than eight, and, later, about every three seconds was the average without computers (and back around with computers it used to be much longer, maybe up to a couple of minutes), so let’s say four and nine seconds as the general idea nowadays. The grabber is four seconds between blinks in real life or nine seconds between blinks when staring at the computer.

Total Blindness While Awake

A lot: In real life, our vision is impaired for about one eighth of the time we’re awake. That’s two hours a day, not counting normal sleeping time. The median blink and near-blink indirection time being about half a second and the interval with normal scenery being four seconds, taking out half a second every four seconds costs us two hours of our waking time. So, we try to compromise, cut corners. With a computer, that drops to one eighteenth; and that’s less than an hour, which is tempting. Another hour of computer work sounds good. And it really sounds good to our bosses.

5-Minute Test

You could try a bigger experiment, if you’re healthy.

Get a clock that shows seconds. Be somewhere comfortable, with nothing threatening, exciting, or visually concerning. Turn televisions and computers off. The air should be still: no wind or fan blasting into your face.

Don’t blink. Keep your eyes open for five entire minutes. If you blink even once, start again. If you have to restart a few times, stop the test. Because there’s no tension or distraction, you’ll be more aware of your discomfort with your eyes. If you start to get uncomfortable, end the test. Since this is about headaches and burning eyes, if no discomfort occurs you shouldn’t get any worse, so your subjective discomfort is a good measure, besides being safer. If you tough it out and then get a headache or a dry eye, stop the test and don’t start again.

Five minutes drag to almost forever. You probably will never finish the test.

And So . . .

When you’re not tired and the normal blink rate obtains, impairment lasting half a second means it takes a whopper out of your waking hours. Thus, the total lost time while awake is normally about seven and a half minutes an hour. But when we use a computer, that drops to just over three minutes an hour. We like gaining four minutes plus of productivity every hour, and that’s not insignificant, but our eyes want to be natural. Maybe the better choice is to save on doctors’ bills and remember that it’s a computer and not a crocodile; and remember to blink.

People Consequences

First to Blink is a Rotten Egg

Who’ll blink first is a benchmark, and not just a metaphor. Two people in a conflict stare each other down, whether the conflict is physical or mental, like between soldiers or lawyers. Both combatants demand control, immediate and total. There’s no blink fast enough to shield you from turning vulnerable in front of an adversary.

We prioritize, but that’s not good enough. Animals and people vary; some are of little interest, some alarm us, and some thrill us. Those of little interest we blink at by default, like they’re nothing. Those we have to attend to constantly will require us to get relief now and then.

Real-Life Tension

Sports are crammed with tense minutes. In basketball, close contacts come in rapid sequence regardless of where the ball is. Players go through consecutive whole minutes when one blink can mean losing. Players, coaches, and fans have high stakes riding on split-second timing. It’s a fair bet that blink rates slow during play. It may be a skill: Judging when to blink may be an unconscious skill among players.

Even something solid, near, and familiar cannot be seen, when it’s too quick. “. . . . Ted . . . . Williams was perhaps the greatest hitter of all time, a man revered for his knowledge and insight into the art of hitting. One thing he always said was that he could look the ball onto the bat, that he could track it right to the point where he made contact. But [tennis coach Vic] Braden knew from his work in tennis that that is impossible. In the final five feet of a tennis ball’s flight toward a player, the ball is far too close and moving much too fast to be seen. The player, at that moment, is effectively blind. The same is true with baseball. No one can look a ball onto the bat. ‘I met with Ted Williams once,’ Braden says. ‘We both worked for Sears and were both appearing at the same event. I said, “Gee, Ted. We just did a study that showed that human beings can’t track the ball onto the bat. It’s a three-millisecond event.” And he was honest. He said, “Well, I guess it just seemed like I could do that.”’” That’s from journalist Malcolm Gladwell. Probably, he sincerely thought he could see it. The brain wants order and it’s likely it would have extrapolated the remaining travel from what it already knew. While his extrapolation may have helped him do a better job of hitting the ball, three milliseconds may be too short for the brain to continue perceiving the ball, or even to realize it no longer sees the ball.

It’s not just Ted. Any batter faces the pitcher. The pitcher is about 65 feet away, and will throw the ball fast at about a mile a minute, and often a lot faster. The pitcher leans back and heaves the missile; that’s the dramatic announcement of what’s coming. Then the ball departs the hand. Within two thirds of a second, it’ll whiz within three feet of the batter’s head at a speed likely above the highway limit. Often it’s less than two thirds of a second for the travel. The batter, meanwhile, has to decide whether to swing at this pitch or wait for the next one, if will swing has to decide at what height to swing it, and, for maximum hitting power, has to swing the bat through a full arc. (That assumes that a decision whether to bunt or swing was made beforehand and not at that moment.) If the batter starts to swing and stops, it generally counts against the batter as a strike, so the decision must be made early. Once a swing is begun, its height can’t be changed without weakening the impact on the ball, and since the usual goal of hitting is distance, weakening is a bad idea, therefore the decision about the height of the swing has to be made early.

So, the batter doesn’t have the whole travel time of the pitch to decide. At the most, the batter has half that time. During that first half, the ball is no more than halfway to the batter, is flying fast, and is tiny, and the batter has to observe the ball’s angle and height. The batter also has to have seen the pitch itself well enough to know if the pitch is fast or slow, if it’s likely to cross the batter’s strike zone, and if the ball may curve in flight. If it’s going to curve, that’s from the last, final twist of the pitcher’s hand at the release of the ball. The batter has to see the pitcher’s hand twist — talk about a subtlety, that’s one. Maybe half a second of observation is critical, and, because none of it provides redundant information, no part of it can be omitted. A blink lasts about half a second. That’s too long. Since an average batter is expected to hit balls about a quarter of the time they’re at bat, according to the Major League Baseball organization and given what they’re paid, no batter who can help it will blink through a pitch. And they have it easy: Unlike some other players, two seconds later the batter can blink all they want. But not at bat.

Getting Reoriented (Advanced Psychology)

When we see a change, we can’t relax. The change causes an orienting response. This means we orient ourselves to the change itself. We pay attention precisely because a change has occurred and we presume it must be important. We do the same when we watch television, only computers are interactive, so computers are more demanding. You don’t get fired for missing a television ad, and that’s a whole minute long. You might get fired for ignoring what flashed by on your work computer, in just seconds. And, if it happens too many times in a minute, we lose track of what’s going on. We pay a lot of attention but barely keep up with all the new information. So we devote even more attention to it. If we can’t slow the computer down, the least we can do is look at it more. Without a blink, if we can help it.

Solving This

Two to Tango

Solutions are about both us and them.

Newer scientific research should always be considered. What you do with it is your call, but you should consider it.

Whatever solutions we choose, we have to make computers yet more comfortable. We’ve made screen flicker a relic of the past. We can design software to be more sensitive to our humanity. There shouldn’t be a dry eye in the house.

Me, Me, Me

Coincidence or Conspiracy

Some issues merely coincide with computer usage. Environmental factors, such as the air you breathe, can sometimes be isolated by determining if your problems using a computer go away when you take your computer somewhere else, like outdoors. If the same computer and the same work in a different environment means the problem disappears, the environment was at fault and the computer is exonerated.

Dumb Brain

We need to remember to blink. I know; I know: That’s stupider. You’ve been blinking a few times a minute while awake since you were born and you’re still busy. I might as well remind you to pump your heart. You were taught to walk, talk, and play by yourself. No one had to teach you to blink. Amnesiacs probably don’t forget how. Whales blink. But the computer rewards us for not blinking and that has become subconscious. We just go along to get along. It’s become a habit.

But it doesn’t work that way when we’re stressed. Sometimes, we have to consciously remember to blink. We have to give it a thought. It’s the thought that counts, definitely.

An optometrist in basically agreed. “I want them [“people who I suspect are having trouble blinking enough”] to think about blinking so they will be a little more conscious of blinking correctly as they work with their VDT [video display terminal (what they used to call a computer monitor)].

All that’s needed is some middle-of-the-brain semi-consciousness. When other people are talking about exciting things in their lives, you don’t have to tell about great blinks. You don’t have to keep a scorecard, consult a guru of the pupil, or pay a coach to set Olympic records with flashing lashes.

You should know when you’re doing stuff that’s leading you to freeze your lids in the up position. You can notice when your eyes are beginning to be just a touch uncomfortable.

Find the rhythm of your work. Maybe when you pound the keyboard, which you already know pretty well, remember your eyes. Or when screen images are rolling past, notice which parts are less important to read and flutter then, so you can be attentive when it’s critical and yet keep your eyes fresh. If the computer is too unfamiliar, such as if you’re trying a new program and you don’t know what’s going to happen next, take a lot of half-second breaks, or pause for a couple of seconds every moment or so, short enough and often enough that no one notices but your eyes stay damp. You can do it so your barking boss hovering over your shoulder doesn’t notice. And your productivity over time will improve. So will your health, and for this you won’t need a pill.

Look at Real Life

Look away, once in a while. Revert to your normal focus and depth perception. Even a pile of papers will give you that.

Okay, typing a thousand phone numbers is exciting and you can’t tear your eyes off them. Try anyway.

Professional advice keeps saying this: Apply the 20-20-20 rule: Every 20 minutes, look away at something 20 feet from you for 20 seconds. (You can read about 20-20-20 when you like.) I suggest it not be a TV (too flat). Look at something interesting and tell your boss it’s on medical advice (since it is).

Emotional Distance

You may distance yourself from your work, like a secretary typing a letter without caring about its content or style. If mental distancing relaxes you, your vision may be all the better for it, as you sometimes look away at other things and still get your work done.

Further Basic Reading

Nerds and Geeks Have a Task

What the “them” have to do is keep redesigning the computer, including the software. Computers should operate the way you need. It’s not your job to be like a computer yourself. You’re no good at that anyway. And plenty of people know how to tweak and redesign.

It’s gotten better over the years. Our blink rate while staring at the box is not as bad as it was maybe 15–20 years ago. There’s still room for improvement.

A computer’s user interface should allow us to work faster and still be healthy. And it isn’t just a database issue. Many kinds of applications have the same problem, maybe in different ways, like when you scroll through a long memo hunting for certain paragraphs. What we know is that computer output needs to be generally consistent with our common-sense expectations and, when that can’t be, to foreshadow when possible. Hardware is not a problem; if you have screen redraw slow enough to matter, you have old hardware, and no one’s going to redesign that for less than the price of upgrading. Software, however, is eligible for improvements; it’s also cheaper or free and can be brought in and installed in a few minutes to an hour or so. A major problem I find with software, especially in the open-software space, is that designing and improving it is usually up to geeks, and they tend to think in geeky ways, so that the technical quality is high but it tends to be user-hostile instead of user-friendly. Microsoft Windows is friendlier while of lower quality than is Linux; but reprogramming is limited mainly to Microsoft and is framed by larger business considerations that seem to get in the way of top technical quality.

A speed governor that is machine-dependent and that a user could adjust would be useful. We already know about governors. They control speeds on many motor vehicles. A bus line may decide that 70 miles per hour is as fast as any driver should ever need. Even if engines are capable of more, the company might install governors, so that if a driver flattens the gas pedal 70 miles an hour is still the top velocity. Fewer crashes come. Fewer tickets, too. In a computer, a speed governor could make a single click serve like the long series of clicks, and a second single click could stop the effective clicking operation. With this, perhaps a single click could cause records to browse like a movie or regulate page scrolling, until the second single click. A user setting might keep records on screen for, say, one second each or half a second each. The governor should be at the operating system level, configurable by users and available to all applications. Each application should self-optimize by implementing the governor’s settings according to the type of application and can offer a user more settings. An operating system already queries hardware for timings. After taking measurements, it can match them to average human preferences, with median, fast, and slow options, and offer an application programming hook.

Realism for older users might provide a good choice. Some Linux distributions come with multiple desktop environments from which a user can choose, and vendors like Microsoft and Apple could offer either a selection of GUIs or a setting to flip some design assumptions.

A simple idea that only a few people will like would be a reminder to blink, flashed by the computer every five seconds or so, coordinated with other on-screen work so as not to obliterate anything (and probably slightly lengthening the display time immediately before and after the flashing to compensate for the loss of concentration on the main task). Placing this at the operating system level would make it available regardless of applications running but the coordination would depend on an app recognizing this service. When this runs likely should depend on which user is logged in.

Occupational safety and health regulations could include speed limits for most users. Artists, computer engineers, and experimenters, among others, may have good reason for exceptions. But secretaries probably clock more time on computers in total than do executives, and students probably use the things more than their instructors do, if students outnumber instructors around thirty to one. Good reasons to overspeed students and secretaries are probably hard to come by. Given that, waiting for governments to write regulations is not necessary. Standards can be written by employers and schools, starting with those who pay for workers’ health care. Applying standards can be done without software governors by limiting the amount of work per hour someone has to perform. That’s a faulty system, and software governors will help ensure consistency and health. But even a manual limitation is a start.

Alerts shouldn’t be dismissible by accident, and a stream of typing shouldn’t disappear because of an alert you didn’t see, because you’re looking at paper. Programmers can design alerts so that typing that’s irrelevant to an alert would disable use of the Enter key to dismiss an alert. You’d have to mouse it away or you’d have to stop typing a while, long enough to see the screen, and then the Enter key would work again, to dismiss the alert.

You’re Innocent

It’s not your fault.

Computers were designed mainly by people who were into computers. But the rest of us mostly just want to use them because of our other duties and interests. Computer geeks are often younger, with eyes that are more resilient and whose bodies have fewer disabilities, so health issues come to mind less often.

You have to make up for their deficiencies. I’m sure they’re sorry about that. Keep blinking in mind and you’ll have fewer headaches.