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The 20-20-20 rule for eye strain

Every 20 minutes, look at something at least 20 feet away for at least 20 seconds.

ZenFlow · · 2 min read

A person pauses at a laptop and looks out a window toward a distant tree.

  1. 20

    minutes

    at the screen

  2. 20

    feet

    to a distant target

  3. 20

    seconds

    holding that view

Try this

  1. Set a 20-minute reminder. The American Optometric Association says a timer helps.Reference [6]
  2. Look at a real object about 20 feet away, such as a window or a far wall. Another screen still counts as near work.Reference [1]
  3. Hold that view for at least 20 seconds.
  4. Sit about an arm’s length from the monitor, with your gaze slightly downward, and blink on purpose. People usually blink about 15 times a minute, and about 5 to 7 times while using a screen.Reference [2]Reference [3]
A person working at a desktop monitor placed across the desk, about an arm's length away.
Keep the screen near arm’s length, and look slightly downward.

What the evidence says

The American Academy of Ophthalmology and the American Optometric Association both publish this habit. The Academy says the discomfort does not injure the eye and is not thought to cause lasting damage.Reference [1]Reference [2]Reference [3]

In 2023, Talens-Estarelles and colleagues gave 29 symptomatic computer users two weeks of 20-20-20 reminders. Strain and dry-eye symptoms fell while the reminders were on (p ≤ 0.045). A week after the reminders stopped, that improvement was gone. Tear-film signs did not change.Reference [4]

A separate lab study of 30 young adults found that 20-second breaks during one 40-minute reading task did not change symptoms, speed, or accuracy (P = .70).Reference [5] If 20 seconds leaves your eyes tight, the Optometric Association also suggests 15 minutes away from the screen after two hours.Reference [3]

See an eye doctor if your eyes stay red, blurry, or watery, or if they become sensitive to light or painful.Reference [1]Reference [2]

This is a short summary of public guidance and two published studies. It is not a diagnosis or a treatment plan.

References

  1. Vimont C. Eye strain and sleepy eyes. Reviewed by Barber LG. American Academy of Ophthalmology. May 5, 2023. aao.org/eye-health/diseases/what-is-eye-strain (opens in a new tab)
  2. Computers, digital devices, and eye strain. Reviewed by Huffman JM. American Academy of Ophthalmology. June 27, 2024. aao.org/eye-health/tips-prevention/computer-usage (opens in a new tab)
  3. Computer vision syndrome. American Optometric Association. aoa.org computer vision syndrome (opens in a new tab)
  4. Talens-Estarelles C, Cerviño A, García-Lázaro S, Fogelton A, Sheppard A, Wolffsohn JS. The effects of breaks on digital eye strain, dry eye and binocular vision: testing the 20-20-20 rule. Cont Lens Anterior Eye. 2023;46(2):101744. PMID: 35963776. DOI (opens in a new tab) · PubMed (opens in a new tab)
  5. Johnson S, Rosenfield M. 20-20-20 rule: are these numbers justified? Optom Vis Sci. 2023;100(1):52-56. PMID: 36473088. DOI (opens in a new tab) · PubMed (opens in a new tab)
  6. Eye-friendly workspace. American Optometric Association. Workplace infographic (PDF) (opens in a new tab)