20-20-20 Rule Break Calculator
Count the eye-rest breaks a day of screen work needs under the 20-20-20 rule and the time they take.
How it works
breaks = screen minutes ÷ interval · rest time = breaks × break length
The 20-20-20 rule for digital eye strain says that every 20 minutes you look at something about 20 feet away for at least 20 seconds. That brief change of focus relaxes the eye muscles held tense by close work and encourages a few full blinks, which counters the dryness of staring at a screen. This tool counts how many breaks a screen day calls for and how little total time they cost.
Worked example
An 8-hour screen day is 480 minutes; at one break every 20 minutes that is 24 breaks, and at 20 seconds each only 8 minutes of eye rest in total.
Sources: American Academy of Ophthalmology — Computers and eye strain
Frequently asked questions
Does the 20-20-20 rule protect my vision long-term?
It eases the temporary discomfort of digital eye strain — tired, dry, achy eyes — but it is not proven to prevent nearsightedness or lasting damage. It is a comfort habit, not a cure.
Why 20 feet?
At roughly 20 feet the eye’s focusing muscle is essentially relaxed, so looking that far briefly gives close-focused muscles a genuine rest.
What else helps screen eye strain?
Blinking fully, good lighting, adequate screen distance, and occasional longer breaks all help. Persistent strain or headaches are worth an eye exam.
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This is a general educational estimate, not medical advice. Individual responses vary — for decisions about exercise, sun exposure, heat, cold or health conditions, talk to a qualified professional.