Effects of head-mounted display on the oculomotor system and refractive error in normal adolescents

Purpose: To investigate the clinical effects of headmounted display on the refractive error and oculomotor system in normal adolescents. Methods: Sixty volunteers (age: 13 to 18 years) watched a three-dimensional movie and virtual reality application of head-mounted display for 30 minutes. The refractive error (diopters [D]), angle of deviation (prism diopters [PD]) at distance (6 m) and near (33 cm), near point of accommodation, and stereoacuity were measured before, immediately after, and 10 minutes after watching the head-mounted display. The refractive error was presented as spherical equivalent (SE). Refractive error was measured repeatedly after every 10 minutes when a myopic shift greater than 0.15 D was observed after watching the head-mounted display. Results: The mean age of the participants was 14.7 ± 1.3 years and the mean SE before watching head-mounted display was -3.1 ± 2.6 D. One participant in the virtual reality application group was excluded due to motion sickness and nausea. After 30 minutes of watching the headmounted display, the SE, near point of accommodation, and stereoacuity in both eyes did not change significantly (all P > .05). Immediately after watching the headmounted display, esophoric shift was observed (0.6 ± 1.5 to 0.2 ± 1.5 PD), although it was not significant (P = .06). Transient myopic shifts of 17.2% to 30% were observed immediately after watching the head-mounted display in both groups, but recovered fully within 40 minutes after watching the head-mounted display. Conclusions: There were no significant clinical effects of watching head-mounted display for 30 minutes on the normal adolescent eye. Transient changes in refractive error and binocular alignment were noted, but were not significant.