Screen Time Eye Strain Calculator

Check your digital eye-strain risk. This free screen time eye strain calculator weighs your daily hours, longest stretch and viewing distance, with 20-20-20 break guidance and ways to ease strain.

This is a general guide to digital eye strain (computer vision syndrome), not medical advice. Screen use doesn’t permanently damage eyes, but it can cause tired, dry or sore eyes and headaches. If you have persistent eye pain, blurred or double vision, or other concerns, see an optometrist or doctor.
Your screen time
hours
hours

Enter your daily screen time and the longest stretch you usually go without looking away. The calculator estimates the breaks you’d take under the 20-20-20 rule and a rough strain-risk level.

Eye-strain risk
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Enter your screen time
20-20-20 breaks / day
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Break time total
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Longest stretch
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Screen-free target
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The 20-20-20 rule: every 20 minutes, look at something about 20 feet (6 m) away for at least 20 seconds. It relaxes the focusing muscles and prompts blinking, which eases dryness. Good lighting, screen distance and regular breaks matter more than total hours alone.

Use this free screen time eye strain calculator to gauge your digital eye-strain risk. Enter your daily screen hours and longest stretch to see breaks needed and a risk level.

What this screen time eye strain calculator does

This eye strain calculator estimates your risk of digital eye strain (computer vision syndrome) from how long, how continuously and how close you use screens, and how many 20-20-20 breaks that implies.

The 20-20-20 rule

Every 20 minutes, look at something
about 20 feet (6 m) away for 20+ seconds.
breaks per day ≈ screen minutes ÷ 20

So 8 hours of screen time suggests around 24 short breaks across the day to rest your eyes.

Signs of digital eye strain

Symptom Common cause
Tired, sore eyes Long unbroken focusing
Dryness / irritation Reduced blinking at screens
Headaches Glare, poor lighting, close distance
Blurred vision Focusing fatigue

How to reduce eye strain

Follow the 20-20-20 rule, keep the screen about an arm’s length away and slightly below eye level, match brightness to the room, reduce glare, and blink often. Screen use doesn’t permanently harm eyes, but these habits keep them comfortable.

How to use the eye strain calculator

  1. Enter total daily screen time.
  2. Add your longest unbroken stretch and viewing distance.
  3. Read your risk level and recommended breaks.

Eye Strain FAQ

What is the 20-20-20 rule?

Every 20 minutes, look at something about 20 feet (6 m) away for at least 20 seconds. It relaxes your focusing muscles and encourages blinking.

Does screen time damage your eyes?

There's no strong evidence it causes permanent damage, but it can cause temporary digital eye strain — tired, dry or sore eyes and headaches.

How do I reduce eye strain from screens?

Take regular breaks, keep the screen about an arm's length away and slightly below eye level, reduce glare, match brightness to the room, and blink often.

How many breaks should I take?

Roughly one short break every 20 minutes — about 24 across an 8-hour screen day under the 20-20-20 rule.

Why do my eyes feel dry at the screen?

People blink far less when focusing on screens, which dries the eyes. Conscious blinking and breaks help restore moisture.

Is the eye strain calculator free?

Yes, this screen time eye strain calculator is completely free, needs no sign-up, and gives instant results in your browser.

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