Effect of ten-minute virtual reality usage on binocular–oculomotor function

Context: The increasing popularity of virtual reality (VR) head-mounted displays necessitates research into their effects on visual function, particularly binocular–oculomotor balance, given the potential for visual strain during use. Aims: The aim of this study was to investigate the effect of playing games using VR for 10 min on binocular–oculomotor function. Study and Design: This was an experimental Study. Subjects and Methods: Thirty-four (34) young, healthy subjects (13 males and 21 females) were studied with a mean age of 22.5 ± 1.5 years. All subjects were required to perform two sessions: one was the control session (close eye when wearing VR), and another was an experimental session (play games on VR). Heterophoria and fixation disparity were measured using the modified Thorington technique and Mallet unit, respectively, at a distance (3 m/6 m) and near (40 cm). Accommodative convergence/accommodation (AC/A) ratio was also calculated. Results: During the control session, a significant esophoric shift for distance horizontal heterophoria (mean = −0.79 ± 1.07 ∆ to − 0.66 ± 1.04∆; P = 0.027) and a reduction in the AC/A ratio (mean = 5.40 ± 0.81∆/D to 5.32 ± 0.84∆/D; P = 0.040) was found. During the experimental session, the near-horizontal heterophoria had a significant exophoric shift (mean = −2.71 ± 2.67 ∆ to − 3.59 ± 3.20∆; P = 0.002) and near-vertical heterophoria showed right hyperphoric shift (mean = −0.07 ± 0.33 ∆ to 0.07 ± 0.43∆; P = 0.016), whereas there was decrement in AC/A ratio (mean = 5.35 ± 0.89∆/D to 5.11 ± 1.05∆/D; P = 0.042). When the mean changes were compared between the sessions, significant differences were found in the distance horizontal heterophoria ( P = 0.041), near-horizontal heterophoria ( P = 0.004), and near-vertical heterophoria ( P = 0.016). No changes in fixation disparity were found during both sessions. Conclusion: While prolonged VR use is known to affect oculomotor balance, we found statistically significant heterophoria changes (especially at near) after 10 min. Crucially, these shifts were not clinically significant. This suggests that oculomotor balance remains reasonably resilient during brief VR exposure. These data inform clinical guidelines, indicating that the immediate effects of short-duration VR are benign.