Why do we blink less at a screen?

If your eyes burn, redden or feel gritty after a long day at the computer, one of the most common reasons is surprisingly simple: we forget to blink while we look at a screen.

Blinking drops at the screen

At rest, an adult blinks roughly 15–20 times a minute. Focusing on a screen lowers that clearly: in a study published in 1993, blinking fell from about 22 times a minute at rest to about 7 while using a display. Another study measured an even larger drop.

Some of the blinks that do happen at a screen are also incomplete: the lid does not close fully, and the tear film is not spread evenly.

Why that dries the eye

Every blink spreads a thin tear film over the front of the eye. When blinks become rare, the film thins and breaks up in between, and the surface dries. The result is often burning, grittiness, redness and blur that clears when you blink, usually worse by evening.

What helps day to day

• The 20-20-20 rule: every 20 minutes, look at something about 20 feet (6 metres) away for 20 seconds. The American Academy of Ophthalmology recommends this break.
• Blink fully and on purpose: now and then, close your lids completely and open them again.
• Place the screen slightly below eye level; looking down keeps the eye less wide open.
• Keep air from air conditioning, fans or heaters from blowing straight at your face.
• Use lubricating drops such as artificial tears after asking a pharmacist or eye doctor.

When to see an eye doctor

If symptoms continue despite breaks, or you have eye pain, marked redness, sensitivity to light or any change in vision, see an eye doctor. Dry eyes can have many causes besides screens.

Where EyeBlink fits

The hard part is remembering to blink. EyeBlink is a small, realistic eye that sits in the corner of your screen and blinks every 4 seconds by default, 15 times a minute. When you notice it, you blink too, and over time it becomes a habit. It sends no notifications and never watches your screen. EyeBlink is not a medical device and does not replace care.