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20-20-20 Rule Eye Strain Calculator
Personalized break schedule for your screen hours.
In this article
The 20-20-20 rule
Every 20 minutes, look at something 20 feet away for 20 seconds. This relaxes the ciliary muscle in your eye that contracts while focusing on a screen, reducing digital eye strain (asthenopia).
Signs of digital eye strain
- Dry, itchy, or burning eyes
- Headaches (especially behind the eyes)
- Blurry vision after screen use
- Neck and shoulder tension (related to screen position)
⚡ CalcWolf Insight
The 20-20-20 rule reduces digital eye strain symptoms by 50-70% according to the American Academy of Ophthalmology.
Frequently asked questions
Does the 20-20-20 rule actually work?▾
Yes — research shows it significantly reduces eye strain symptoms. Set a timer app or use tools like Time Out (macOS) or EyeLeo to automate it.
Do blue light glasses actually work?▾
Research is mixed. The American Academy of Ophthalmology does not recommend blue light glasses for digital eye strain. Most eye strain comes from focusing at a fixed distance, not from blue light itself. The 20-20-20 rule, proper screen distance, and adequate lighting are more effective interventions.
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