SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/screen-20-20-20-rule

Your eyes feel tired after a long time on a screen. What's the eye doctors' break rule?

20-20-20: every 20 minutes, look 20 feet away for 20 seconds.

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The Just Right card

Too littleStare at the screen for hours straight
Too muchStop all screens for a week
Just rightLook 20 feet away for 20 seconds regularly

Huh, didn't know that: People blink only three to seven times a minute at a screen, and blinking less dries the eyes' surface.

The dad joke
What do you call an eye doctor living on an island? An optical illusion.
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References

Answer: Every 20 minutes, look 20 feet away for 20 seconds. Screens make your eyes refocus often, and you blink less. Looking at least 20 feet away for about 20 seconds every 20 minutes gives your eyes a regular break.

  1. Cleveland Clinic: Computer Vision Syndrome my.clevelandclinic.org/health/diseases/24802-computer-vision-syndrome
    Every 20 minutes, look at something at least 20 feet away for about 20 seconds.
    Checked 2026-10-09.
  2. Cleveland Clinic: Computer Vision Syndrome (blinking) my.clevelandclinic.org/health/diseases/24802-computer-vision-syndrome
    You blink three to seven times a minute when you look at a screen.
    Checked 2026-10-09.

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