Abstract
Purpose :
The use of digital devices has increased substantially over the past two decades across all age groups for both vocational and avocational purposes. Today, the use of digital screens is almost universal. Digital eye strain (DES) involves a range of visual and ocular symptoms that can be categorized into oculomotor/refractive abnormalities or dry eye symptoms. There are a wide range of proposed therapeutic and management options for this condition, including optical, medical and ergonomic interventions. Regular breaks are frequently recommended by clinicians. Indeed, the so-called 20-20-20 rule, whereby individuals are advised to fixate on an object at least 20 feet (6m) away for at least 20 seconds every 20 minutes is widely cited. Unfortunately, there is little or no peer-reviewed evidence to support this so-called rule. The aim of the present investigation was to determine whether scheduled breaks are indeed effective in reducing the adverse effects of digital device usage, and if so, to identify the specific schedule that has the greatest success in controlling symptoms.
Methods :
The study was performed on 30 young, visually-normal subjects who were required to perform a 40-minute, cognitively demanding reading task from a tablet computer. The task required them to read random words and to identify which began with a specific letter chosen at random by the experimenter. The task was undertaken on four separate occasions, with 20-second breaks being allowed every 5, 10, 20 or 40 (i.e., no break) minutes, respectively. Both before and immediately after each trial, subjects completed a questionnaire regarding ocular and visual symptoms experienced during the session. Additionally, both reading speed and task accuracy was quantified during each trial.
Results :
A significant increase in post-task symptoms (with respective to the pre-task value) was observed for all four trials (p<0.001). However, there was no significant effect of scheduled breaks on reported symptoms (p=0.70), reading speed (p=0.93) or task accuracy (p=0.55).
Conclusions :
While widely cited as a treatment option, these results do not support the proposal of using scheduled breaks as a therapeutic intervention for DES.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.