Using the 20-20-20 rule (taking a 20 second break to view an object 20 feet away after 20 minutes of computer work) reduces digital eye strain (DES) and dry eye symptoms, according to a study published in Contact Lens and Anterior Eye. However, using this strategy failed to improve binocular vision or dry eye signs over a 2-week period.
Researchers enrolled 29 symptomatic volunteers (20 women; mean age, 27±7 years) in a prospective, longitudinal, controlled clinical study to evaluate the efficacy of the 20-20-20 rule. Participants underwent visual acuity, accommodative posture, stereopsis, fixation disparity, ocular alignment, accommodative facility, positive and negative vergence, and near point of convergence assessment at baseline and subsequent follow-up visits. Tear meniscus height, conjunctival redness, blink rate, lipid layer thickness, non-invasive keratograph break-up time, corneal and conjunctival staining, and lid wiper epitheliopathy were obtained to evaluate dry eye signs.
Subjective assessments, including the computer vision syndrome questionnaire, ocular surface disease index (OSDI), and versions 1 and 2 of the symptom assessment in dry eye questionnaire (SANDE), measured dry eye and DES symptomatology.
All participants used their computers a mean 7±2 hours per day, 6±1 days per week. A bespoke computer software program with a webcam monitored breaks, eye gaze and blinking among participants during the study duration. For the first 2-weeks, participants were not reminded to take routine breaks. During the second 2-week period, personal reminders surfaced on participants’ computers reminding them to adhere to the 20-20-20 rule.
Overall, participants decreased their computer work and break duration and increased the number of breaks taken per day when receiving 20-20-20 rule reminders (P ≤.015). Dry eye symptoms and DES decreased with the reminders (P ≤.045), but these improvements did not continue 1 week after discontinuing software use (P >.05).
No changes were observed in any binocular parameter after the 2-week period (P ≥.051), except for an increase in accommodative facility (P =.010). Even with the reminders, no changes were observed on any ocular surface or tear film parameter (P ≥.089).
“[E]nabling the 20-20-20 rule reminders had a significant impact on how participants used their computers,” according to the researchers. “Participants took more breaks per day in total when the 20-20-20 rule reminders were on compared to when they were off (34 with reminders on vs 27 with reminders off), which was partially attributed to the breaks taken following the instructions of the reminders.”
Study limitations include a potential placebo effect, possible fatigue due to a large number of tests, and a failure to consider the use of other digital devices besides the computer.
Talens-Estarelles C, Cerviño A, García-Lázaro S, Fogelton A, Sheppard A, Wolffsohn JS. The effects of breaks on digital eye strain, dry eye and binocular vision: testing the 20-20-20 rule. Cont Lens Anterior Eye. Published online August 10, 2022. doi:10.1016/j.clae.2022.101744