Digital eye strain symptoms worsen during prolonged digital tasks, associated with a reduction in productivity

Purpose: It is often stated that digital eye strain can impact productivity and/or work accuracy, but the relationship between symptoms, productivity, and work accuracy has been unclear. Hence this study tracked the development of visuo-ocular symptoms during prolonged digital tasks and to explore the impact of higher and lower cognitive load levels on visuo-ocular symptoms, productivity, and work accuracy. Methods: Thirty-five participants (23.2 +/- 4.0 years) who had digital eye strain (diagnosed with the Computer Vision Syndrome Questionnaire) undertook an uninterrupted laptop adapted Eriksen Flanker task for 60 min on two separate days, once with a high cognitive load in randomised sequence. Symptoms were assessed at baseline and every 10 min throughout the task. Results: All visuo-ocular symptom scores significantly worsened (F = 87.783, p < 0.001) with time, with the symptom severity increasing faster with the higher cognitive load (F = 7.110, p < 0.001). The mean total number of tasks completed was greater for the lower (1060.8 +/- 296.5) than the higher (532.2 +/- 123.4) cognitive load tasks (F = 138.830, p < 0.001), reducing with time (F = 7.339, p < 0.001), but in a similar way for both cognitive loads (F = 1.795, p = 0.154). Task accuracy was not affected by the cognitive load of the task (F = 1.729, p = 0.197) and was consistent over time (F = 1.885, p = 0.135). Conclusions: Symptoms increased with task duration in individuals with digital eye strain, with a faster rate for more demanding tasks. This was associated with a decrease in the task completion rate (productivity), but not the work accuracy.