Your eyes are kept comfortable by a thin tear film that is spread across the surface every time you blink and evaporates in between. Anything that makes you blink less, or blink badly, lets that film break up before the next blink arrives. The result is the dry, burning, sandy feeling that so many people associate with a long day at the computer.

The good news is that most of the causes are habits and surroundings rather than anything wrong with your eyes, which means most of the fixes are cheap and quick.

It starts with blinking

The usual claim is that we blink far less at screens. The research is more interesting than that. When Rosenfield’s group at SUNY College of Optometry compared reading the same material on a monitor and on paper, blink rates were similar: around 15 blinks a minute on screen versus about 14 on paper. What differed was blink quality. On the screen, a significantly larger share of blinks were incomplete, with the upper lid stopping short of the lower one.

An earlier study from the same group found that symptom scores tracked the percentage of incomplete blinks, not the overall blink count. Prompting people to blink more often with an audible cue raised their blink rate but did not reduce their symptoms. In other words, a half blink does not refresh the lower part of the eye, and more half blinks do not help.

Other studies have found that blink rate does fall on screens, particularly during demanding or absorbing tasks, and the American Academy of Ophthalmology states plainly that blinking drops sharply during screen use. The two findings are not really in conflict. Concentration, not the display, seems to be what changes blinking, and screens are where we concentrate hardest.

The takeaway

It is complete blinks that matter. A deliberate, slow blink that closes fully, repeated a few times, does more for a dry eye than a dozen flickers.

What else dries eyes at a desk

  • Screen height. Looking up or straight ahead opens the eyelids wider and exposes more of the surface to the air. The Academy suggests sitting about 25 inches from the screen with your gaze angled slightly downward. A laptop on a stand with the top of the screen above eye level is a common culprit.
  • Dry, moving air. Heating, air conditioning, and desk fans all speed up evaporation. A humidifier in a dry, warm room is one of the Academy’s specific recommendations.
  • Contact lenses. Lenses can make screen dryness worse. Switching to glasses for part of the day, or at least for breaks, is a reasonable experiment.
  • Long unbroken stretches. The two-week study that tested the 20-20-20 rule found that reminders to pause reduced dry-eye symptoms as well as eye strain, even though tear-film measurements themselves did not change in that time.
  • Medications and age. Antihistamines, some antidepressants, and hormonal changes all reduce tear production. If dryness arrived with a new prescription, mention it to your doctor.

What actually helps

  1. Blink fully, on a cue. Use every pause as a prompt for three or four slow, complete blinks. The American Optometric Association notes that complete blinking helps keep the tear film stable, and it costs nothing.
  2. Lower the screen. Bring the top of the display to eye level or a little below, so your natural gaze falls slightly downward and your lids sit lower.
  3. Humidify, and move the airflow. Point fans and vents away from your face. In winter, a small humidifier near the desk makes a noticeable difference.
  4. Use artificial tears when needed. The Academy recommends lubricating drops when eyes feel dry. Preservative-free single-dose vials are the gentlest option if you use them more than a few times a day.
  5. Take regular breaks away from near work. A brief distance break every 20 minutes and a longer stand each hour reduce the overall load on your eyes. Pair each break with the blinks above and you address both halves of the problem at once.
  6. Match brightness to the room, and cut glare. A screen much brighter or dimmer than its surroundings makes you squint and stare. The Academy also suggests a matte filter if reflections are a problem. Our Mac comfort guide walks through the settings.

What probably does not

Blue-light glasses. The Academy does not recommend blue-light-blocking glasses for eye strain or dryness and says digital device light does not damage the eye. Dryness is about evaporation and blinking, not wavelength. Blinking faster. As above, more incomplete blinks did not reduce symptoms in testing; completeness is what counts. Drops with redness relievers. Vasoconstrictor drops whiten the eye without lubricating it and can rebound with regular use. Plain lubricating drops are the better choice.

A simple routine for a dry-eyed afternoon

  1. Lower the screen until your gaze tilts slightly down.
  2. Turn any fan or vent away from your face.
  3. Every 20 minutes, look across the room and blink slowly four times.
  4. Once an hour, stand, stretch, and close your eyes for ten seconds.
  5. Keep lubricating drops in the drawer for the days that still feel rough.

EyeRest Flow can carry most of this for you: it prompts a complete-blink nudge every few minutes, offers “blink slowly” as one of its guided breaks, and waits until you have finished typing before it asks.

When to see someone

Dryness that persists despite the changes above, or that comes with redness, light sensitivity, blurred vision that does not clear with blinking, or pain, deserves a proper examination. Dry eye disease has several causes, from blocked oil glands in the eyelids to inflammation, and each is treated differently. An optometrist or ophthalmologist can tell which you have in a short visit.

Sources

This article provides general information and is not medical advice.