The daily tasks of a modern human differ greatly from the past. Where most of our time used to be spent outdoors gazing into the distance, our eyes are now almost exclusively glued to screens or objects within a few feet of us. We are using our eyes in ways they were not designed to. That being said, it is no wonder why our society faces challenges with eye health and comfort. The 20/20/20 rule refers to a group of habits we can use and adopt to help our eyes cope with the stresses we place them under while we compute, text, or even watch our favorite TV show. 

The first 20 relates to time. After every 20 minutes of near work, whether that be two feet or two inches, we should take a break. Prolonged near work stresses our visual system in ways it has a difficult time coping with. Long bouts of focusing at near can be responsible for eye strain, headaches, and even progression of nearsightedness. The second 20 relates to distance. For our eyes to fully relax we need to focus at a distance of at least 20 feet. This has to do with the way light acts in space. Only by focusing on an object 20 feet away will our eyes be able to fully defocus and relax their gaze. Just like any muscle, the muscles in our eyes that aid in our ability to focus up close can get tired, sore, or even cramp. It is important to let those muscles take a break regularly for them to function at their best.

Also see our blog about OTC medications for dry eyes

The last 20 relates to blinking. When we are focused on something mentally engaging, our brain suppresses the response to blink. This helps us take in more information at a given time. However, this comes at a cost to our eye health. We should be blinking at least 10 times per minute to re-coat the front of the eye with tears and facilitate the natural expression of oils from our eyelids. Without this constant refresher, our eyes get dry, our eyelids get irritated, and the classic symptoms of dry eye disease emerge. 

So, we have the “rule”. For every 20 minutes of near work, it is advised to look 20 feet away, and blink 20 times. This rule may not be practical under every circumstance, and it isn’t meant to be. It is meant to be a framework for how we use our eyes. By having this general structure in mind, it should allow for more frequent breaks with emphasis on relaxing and rejuvenating the eyes. Following these guidelines should allow one to work more efficiently and feel better afterwards. 

Although this is a good starting point for those who may be suffering from dry eyes and/or eye strain after excessive near work, it is important to consider other causes as well. I recommend starting with a comprehensive eye exam to ensure the correct glasses or contacts are in place if needed, as well as treating any other underlying causes of dry eye or headache. If you have questions, talk to your doctor and/or see the links below.
 
References:
https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/computer-vision-syndrome?sso=y
https://www.allaboutvision.com/conditions/refractive-errors/what-is-20-20-20-rule/