20-20-20 Screen Rule: Does it Help Prevent Eye Strain?

Definition

20-20-20 Screen Rule

The 20 20 20 Rule is a safety microbreak concept developed by optometrist Dr. Jeffrey Anshel. The 20-20-20 computer and handheld devices screen rule means that for every 20 minutes of looking at the screen, you should take a 20-second break and focus your eyes on something at least 20 feet away.

Main Digest

The effects of breaks on digital eye strain, dry eye, and binocular vision: Testing the 20-20-20 rule.

It's long been recommended as a way of easing eye strain while working at a computer screen. Now the 20-20-20 rule - taking a break of at least 20 seconds, every 20 minutes, to look at least 20 feet away - has been confirmed by scientists at Aston University to help ease some of the symptoms of prolonged computer use.

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It's estimated that at least half of people using computers in their regular work have some form of digital eye strain, resulting in eye surface problems, including irritation and dryness, or vision issues, such as headaches or blurred vision. Humans normally blink around 15 times each minute. When staring at screens, this number generally decreases to half that rate or less. That can lead to dry, irritated, and tired eyes, but twenty seconds of focusing elsewhere is long enough for the eyes to relax to reduce the strain.

This is the first time that the 20-20-20 guidance rule has been properly validated. Researchers at Aston University's College of Health and Life Sciences set up their study with the help of 29 participants who suffer from symptoms of eye strain.

Special software downloaded onto the participants' laptops used the built-in laptop camera to check if a user was sitting at the screen and to monitor their gaze direction every few seconds.

After 20 minutes of continuous screen viewing, the program flashed a message, asking users to rest for 20 seconds while looking at any distant target around 20 feet away, such as out of the window or across a room. The message couldn't be removed until the task was performed correctly, as measured by the app.

Participants' digital eye strain symptoms were measured before and after two weeks of using the reminders and one week after completing the study. Results showed a marked decrease in symptoms, including dryness, sensitivity, and discomfort.

Professor James Wolffsohn, Professor of Optometry at Aston University, who led the research in collaboration with the University of Valencia, Spain, said:

"The one previous study merely asked people to carry out the suggestions, but here the access control on the software meant we could be sure that participants really had looked away every 20 minutes. We saw a consequent improvement in the symptoms of the group as a whole."

Researchers noted that after the study, the participants' eye symptoms returned to what they had been before the intervention. Professor Wolffsohn says:

"We are planning to conduct longer-term studies to see whether we can teach eyelid muscle memory impulses to blink more often during digital viewing to help mitigate this chronic issue without long-term use of reminders."

The findings confirm that people should try and take screen breaks. He added:

"Although we used sophisticated software, it's easy for others to replicate the effect by setting a timer on their phone or downloading a reminder app. It's a simple way of reminding yourself to take regular breaks for the good of your eyes."

The effects of breaks on digital eye strain, dry eye, and binocular vision: Testing the 20-20-20 rule was published in Contact Lens and Anterior Eye journal.

Attribution/Source(s):

This peer reviewed article relating to our Electronics/Software section was selected for publishing by the editors of Disabled World due to its likely interest to our disability community readers. Though the content may have been edited for style, clarity, or length, the article "20-20-20 Screen Rule: Does it Help Prevent Eye Strain?" was originally written by Aston University, and published by Disabled-World.com on 2022-09-24 (Updated: 2023-01-04). Should you require further information or clarification, Aston University can be contacted at aston.ac.uk. Disabled World makes no warranties or representations in connection therewith.

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