The 20-20-20 rule and digital eye strain

The 20/20/20 rule

We seem to like doing things in 20’s in the optometry world – we often talk about 20/20 vision (that means that you can see anything from 20 feet away that you should be able to see for normal vision).  But in this post we’re talking about the 20-20-20 rule, a rule that may help your eyes to cope in our screen-filled modern day life.

Adjusting your focus with the 20-20-20 rule

What is the 20-20-20 rule and why should we follow it?

The 20-20-20 rule:

For every 20 minutes spent looking at a screen, look away for 20 seconds at something that is 20 feet (6 metres) away.

We recommend following the 20-20-20 rule whenever you are spending time looking at screens.  That includes any screen – computer, TV, phone, or any other digital device.  This exercise allows your eyes, albeit for a brief amount of time, to focus somewhere else. 

When you are looking at screens, you are focusing in the same spot, at the same distance for long periods of time.  Studies have also shown that we also blink less when looking at screens, putting further strain on our eyes. 

Take some time to observe how you use your eyes when looking at screens compared to other activities such as driving, where we switch our focus from near to far all the time, or moving around the house or the shops, where we are looking up and down, close and far, back and forth constantly. 

It’s important to remember that it doesn’t need to be exact.  You can look away for longer than 20 seconds, and something further away and you’ll still be giving your eyes a bit of a break.

Digital eye strain from looking at a screen

What are the symptoms and issues around digital eye strain?

Research by the American Academy of Opthalmology suggests that looking at screens won’t necessarily damage your eyesight, but rather cause eye strain, and other symptoms that we commonly associate with digital eye strain. 

We spoke a bit about this in our post about digital eye strain, but in essence, some of the symptoms you may experience include:

  • Dry eyes
  • Blurred vision
  • Headaches
  • Sensitivity to light
  • Sore neck, shoulders or back
Set a timer to follow the 20-20-20 rule

How can I implement the 20/20/20 rule?

It’s a simple as setting a timer when you are using a screen.  You can use the timer function on your phone, or download one of the many apps available.  If you spend your days working in front of a computer, you could use the break as a chance to step outside (and look out into the distance), giving yourself as well as your eyes a rest.  If you’re watching TV, perhaps have your break when the ads are on, after all, the 20-20-20 rule is flexible. 

Other measures you can take include:

  • Making sure you aren’t sitting too close to the screen
  • Keeping the screen clean (so your eyes aren’t trying to work their way through the dust and grime as well)
  • Blinking lots, and drinking lots of water for hydration of both your eyes (and your body!)
  • Dimming the screen, especially at night if the light around you is lower than the light emitted from the screen.

It can be quite hard to escape prolonged use of screens in our modern world, but the 20-20-20 rule is a simple measure you can implement to give your eyes regular breaks, reducing the chances of developing digital eye strain.

Should you be concerned about your eyes, the first step is always to book in for an appointment.  We can check that there isn’t something more sinister behind your sore eyes, and help you with personalised advice based on your own lifestyle and medical history. 

We also recommend regular appointments, so we can monitor any gradual changes that may be occurring to your eyes.  Sometimes the changes can be so subtle you don’t even realise.  We can pick up on these changes in the early stages, leading to better health outcomes.

This website does not provide medical advice.  It is intended for informational purposes only.  It is not a substitute for professional medical advice, diagnosis or treatment.  Never ignore professional medical advice in seeking treatment.  If you think you may have a medical emergency, immediately dial Triple 0 (000).


American Optometric Association, Visual acuity. Accessed March 2021.

Healthline, How does the 20-20-20 rule prevent eye strain? Accessed March 2021.



The 20-20-20 rule and digital eye strain
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