Why you blink less at the computer, and how to blink more

You blink less when you concentrate on a screen, and a good share of the blinks you do make never close all the way. Between blinks, the thin layer of tears on the front of your eye dries and breaks up, which is a big part of why a long screen day ends with eyes that sting or feel like they have sand in them.

The fixes are simple, and once they are habits they take almost no effort: a few slow, full blinks on purpose, regular breaks that let your blinking reset, damper air around your desk and a screen that sits a little below eye level. This post explains why each one works and how to make it happen without thinking about it.

How often we blink, and what screens change

At rest, people blink something like 15 to 20 times a minute, though the range between people is wide and the exact figure depends on how it is measured. Nobody counts their own blinks, and you don't need to. What matters is the change.

When you concentrate on reading, your blink rate drops. Studies that have watched people at computers have found it falls sharply during screen work, in some cases to a fraction of the resting rate. It is mostly the concentration doing it, not something special about the screen. Reading a book slows blinking too. Screens just get far more of our hours, and we tend to hold our gaze on them without a break.

Studies also suggest that more of our blinks become partial at a screen. The upper lid comes down part of the way and goes back up without meeting the lower lid. It counts as a blink to your brain, but it leaves the lower part of the eye uncovered and doesn't do the job a full blink does.

What a blink is for

The front of your eye is covered by the tear film, a layer far thinner than a hair that keeps the surface smooth and comfortable. It has three parts that work together:

• An oily outer layer, made by glands along the edges of your eyelids, that slows evaporation.
• A watery middle layer, which is most of the tear film.
• A mucus layer next to the eye that helps the tears cling to the surface.

Every full blink wipes the surface clean and spreads a fresh tear film across it. The squeeze of the lids at the end of a full blink also helps push a little of that oil out of the glands and onto the tears. Between blinks, the film thins and starts to break up. Leave it long enough and dry spots appear.

That is where the familiar screen-day feelings come from: stinging, burning, a gritty sense that something is in your eye, and vision that goes slightly soft until you blink. Oddly, dry eyes can also water a lot. When the surface gets irritated, the eye makes a flood of reflex tears, which are mostly water and wash away without fixing the dryness. Watery eyes at the end of a long day can be a sign of dryness, not too many tears.

How to do a slow, full blink

A deliberate blink is not a squeeze-your-eyes-shut affair. It is slow, and it closes all the way.

1. Close your eyes gently, all the way, until you feel the lids meet.
2. Hold them closed for a second or two.
3. If you like, add a very light squeeze, just enough to feel the lids press together, then relax.
4. Open slowly.

Do three or four of those in a row, a few times an hour. Some optometrists give people blink exercises much like this one. The research on them is small, but there is no real downside, and many people find their eyes feel better straight away.

Breaks reset your blinking

The easiest way to blink normally again is to stop concentrating on the screen for a moment. When you look across the room, there is nothing to read, and your blink rate tends to come back on its own. This is one reason the 20-20-20 rule helps: every 20 minutes or so, give your eyes 20 seconds on something 20 feet off. The full guide to the 20-20-20 rule covers the why and how.

You can tie blinking to those breaks. Each time you look away, add three slow blinks. You can also hang them on moments that already happen at a desk:

• After you send an email or a message, before you open the next one.
• While a page loads, a file uploads or a video call connects.
• Every time you pick up your glass of water.

None of these will hit a perfect schedule. They don't need to. The aim is to break up the long stretches of fixed staring that dry the eyes out.

Fix the air around your desk

Dry air makes the tear film evaporate faster, so every long gap between blinks does more damage to your comfort.

• Get the draft off your eyes. An air conditioning vent or a desk fan blowing across your eyes is an easily missed cause of screen-day dryness, and one of the easiest to fix. Move the fan, angle the vent or move the desk.
• Watch out for heating. Central heating dries indoor air in winter. If your room feels dry, a humidifier nearby can help, as can opening a window now and then.
• Mind the commute. If your eyes are already struggling after a day at the screen, a drive home with the air vent on your face makes it worse.

Put the screen a little lower

How wide your eyes are open matters too. When you look straight ahead or up, your upper lids lift and more of the eye's surface is exposed to the air. When you look slightly down, the lids cover more of it and the tears last longer.

That is one reason eye care and ergonomics advice puts the top edge of the screen level with your eyes or a touch lower, so your gaze tips slightly down to what you are reading. A tall external monitor that has you gazing upward all day can quietly make dry eyes worse. A laptop flat on a desk goes too far the other way and pulls your head down. How far your screen should be from your eyes covers distance and height together, with a one-minute way to check your own desk.

If you wear contact lenses, you may feel all of this more, because lenses can make the tear film less stable. If your eyes are fine with glasses and not with lenses at the computer, that is worth raising with your optometrist. Dry eyes at the computer covers lenses, dry air and the other causes of screen-day dryness in more depth.

Let a reminder do the noticing

The hard part of blinking more is that you can't notice you have stopped. Your blinks slow down at exactly the moment you are most absorbed, which is also the moment you are least likely to think about your eyes.

So hand the noticing to something outside your head. In Notchpals, the Eyes characters (Blip, Bill and Blush, one of them in your crew at a time) have a moment called Blink break. The character peeks out of the notch and asks for a few slow blinks, nothing more. Blush, a shy chameleon, makes the request about as gently as it can be made.

BlushSlow blinks, please. Close, open. Like hiding, then peeking. Very me.

Do the blinks, then press Done. If you are halfway through a thought, press Later: the request comes back once, 20 minutes on, and a second Later drops it. Blink breaks draw on the same daily allowance as eye breaks and the rest of your crew's repeating reminders, which you choose as Calm, Normal or Chatty, so they turn up now and then among the others, never every few minutes. That makes them a prompt, not a fix. The habit of hanging slow blinks on things you already do is what covers the hours in between.

When to see someone

Dryness that comes and goes with screen days is very common and usually eases with the changes above. Some things are worth a proper look, though. See an optometrist or a doctor if your eyes are painful, red or sensitive to light, if your vision stays blurry after you blink, if one eye is much worse than the other, or if dryness carries on even on days away from screens.

If you are thinking about eye drops, ask a pharmacist or an eye doctor which kind suits you, rather than picking one at random off the shelf.

For most people, though, the first step takes a few seconds: three slow, full blinks, now and again through the day.