Prevent Eye Strain: Follow the 20-20-20 Rule

By Scott Rutherford

ou’re no doubt familiar with 20/20 vision, that benchmark of visual normalcy that indicates that we can clearly see things that are 20 feet away. But have you heard of the 20-20-20 rule?

Both the American Optometric Association and the American Academy of Ophthalmology endorse the 20-20-20 rule. The rule suggests that, when working with computers or other screen devices, we take a 20 second break every 20 minutes to focus our eyes on something 20 feet away.


It’s no secret that we spend a lot of time looking at computer, tablet, and smartphone screens. This trend has been on the rise for a long time, and the consensus is that the pandemic made the problem worse; even after most of us went back to the office. We seem to have become more dependent than ever on our devices, with more and more of our meetings and other work conducted virtually.


Staring at our screens for prolonged periods can irritate our eyes. Among other things, this is because we tend to blink less while looking at screens – as little as half to a third as often as normal – which reduces tear production and leads to dry, irritated eyes. When we spend too much time staring at our screens, we may also suffer from loss of focus flexibility, which has to do with how quickly we can re-focus when we change what we’re looking at. Most of us lose focusflexibility naturally with age, but, according to Healthline, our screen time can cause us to lose focus flexibility sooner and more quickly than we would otherwise.


In any case, following the 20-20-20 rule can help with both. The point isn’t necessarily to be exact. It doesn’t matter if the object you focus on is exactly 20 feet away, so no need to measure. Just make sure that about every 20 minutes, you’re taking some time to look away from the screen and focus on something distant. Why 20 seconds? According to The American Academy of Ophthalmologists, it’s because it takes an average of 20 seconds for our eyes to relax and focus when we look at something in the distance.


Of course, following the 20-20-20 rule is just one of many ways you can improve your eye health while using devices. Other tips include keeping screens about an arm’s length away, tilting the screen so that you’re looking downward at it, adjusting the screen’s brightness so that it is as close as possible to the lighting in the room (i.e., less contrast), cleaning your screens regularly, wearing blue ray reducing glasses, and using a matte screen filter.