It has been advocated for years as a method of reducing eye strain while working at a computer screen. Now, experts at Aston University have proven that the 20-20-20 rule—taking a break of at least 20 seconds every 20 minutes to look at least 20 feet away—can help alleviate some of the symptoms of extended computer use.
It is believed that at least half of those who regularly use computers for work suffer from digital eye strain, resulting in eye surface problems such as irritation and dryness, or vision difficulties such as headaches or impaired vision. Humans typically blink approximately 15 times each minute. When staring at a screen, this quantity reduces to approximately half or less. This can result in dry, itchy, and strained eyes, but twenty seconds of focusing on something else is sufficient to allow the eyes to relax and alleviate the strain.
This is the first time the 20-20-20 guidance rule has been validated properly.
The College of Health and Life Sciences at Aston University recruited 29 volunteers with eye strain symptoms to participate in their study. Special software downloaded onto the participants’ own laptop computers employed the built-in laptop camera to monitor the participants’ gaze direction every few seconds. After 20 minutes of constant screen staring, the application prompted users to take a 20-second break by gazing at a distant object around 6 metres away, such as out a window or across a room. The notice could not be removed until the app determined that the task had been executed appropriately.
The participants’ digital eye strain symptoms were measured before, after, and one week after utilising the reminders for two weeks. The results demonstrated a significant reduction in symptoms, including dryness, sensitivity, and discomfort.
Cristian Talens-Estarelles et al, The effects of breaks on digital eye strain, dry eye and binocular vision: Testing the 20-20-20 rule, Contact Lens and Anterior Eye (2022). DOI: 10.1016/j.clae.2022.101744