Changes in accommodation with visual fatigue among digital device users

Abstract

Background: Visual fatigue is categorized as a complex phenomenon that decreases visual performance. The aim of the present study was to assess changes in accommodation at different levels of visual fatigue among students of a Malaysian private university using digital devices.
 Methods: In this cross-sectional study, students regardless of sex and ethnicity were included. A comprehensive eye examination was performed. After estimating the level of visual fatigue, the amplitude of accommodation (AA), accommodation facility (AF), and monocular estimation method (MEM) were measured. The visual fatigue questionnaire was filled out by the participants. Participants were categorized based on the visual fatigue scores into low, moderate, and high visual fatigue groups. Moderate and severe visual fatigue groups were combined, as the distribution of participants was uneven across the groups. Accommodation parameters were measured for each group and compared between the two groups, i.e., the low visual fatigue group and the combined moderate to severe visual fatigue group.
 Results: We enrolled a total of 86 students, including 29 (33.72%) men and 57 (66.28%) women, with a mean (standard deviation [SD]) age of 22.02 (1.51) years and age ranging from 19 to 26 years. By ethnicity, there were 69 (80.23%) Chinese, five (5.81%) Indian, four (4.65%) Malay, and eight (9.30%) participants from other ethnicities. Most participants were in the low visual fatigue group (54.65%), followed by the severe (25.58%) and moderate (19.77%) visual fatigue groups. AA for both eyes and AF for the right eye differed significantly between the two groups (both P < 0.05). None of the accommodative parameters correlated with visual fatigue (P > 0.05).
 Conclusions: Binocular AA and monocular AF significantly differed between the visual fatigue groups, but MEM was comparable. However, none of the accommodative parameters correlated with visual fatigue. These perceived vision dysfunctions could affect the visual skills of students. Therefore, future studies on the relationship between the observed dysfunctions and students’ reading performance are necessary.