Screen Break (20-20-20 Rule) Calculator
Calculate your 20-20-20 eye break schedule to reduce digital eye strain.
Find out how many breaks you need per workday.
Digital eye strain (also called computer vision syndrome) affects millions of people who spend long hours looking at screens. Symptoms include dry eyes, blurred vision, headaches, neck pain, and eye fatigue. The cause is a combination of reduced blinking (from 15–20 times per minute down to just 3–7 times when staring at a screen) and the constant muscle effort required to focus at a fixed distance.
The 20-20-20 Rule
Recommended by the American Academy of Ophthalmology, the 20-20-20 rule is simple and highly effective:
Every 20 minutes, look at something at least 20 feet (6 metres) away for at least 20 seconds.
This brief break relaxes the ciliary muscles in your eyes that control lens focus. When you focus on a distant object, those muscles release tension and the lens flattens — essentially giving your eye a micro-rest.
Why 20 Feet (6 Metres)?
At 20 feet (6 m), the light entering your eye is effectively parallel — your focusing muscles are fully relaxed, as if looking at infinity. Any closer and some focusing effort is still required.
How This Calculator Works
- Breaks per day = (Screen hours × 60) ÷ 20
- Total break time = Breaks per day × 20 seconds
This calculation shows how many breaks you need per day based on your screen hours, and how much total break time is involved. It also suggests the optimal schedule for your workday.
Additional Tips
- Blink deliberately: Remind yourself to blink fully and slowly to re-moisturise your eyes
- Adjust monitor distance: Keep your screen 50–70 cm (20–28 inches) away
- Screen brightness: Match screen brightness to your room lighting
- Night mode: Use blue light filters in the evening
- Artificial tears: If dryness persists, lubricating eye drops can help
Most people are surprised to find that 20-second breaks add up to very little total time — less than 5 minutes per 8-hour workday.