EVALUATION OF ACCOMMODATION AND CONVERGENCE FOLLOWING SMARTPHONE USE IN YOUNG ADULTS

ABSTRACT

This study investigated the effect of smartphone usage on the accommodation and convergence of the visual system. A total of 35 subjects, aged between 18 to 30 years, with a mean age of 23.1 ± 0.72 were recruited for this study. This study was carried out in the University of Benin. Case History, Visual acuity test, External and Internal eye examination was performed on each subject to rule out ocular pathologies or strabismus and to ensure they can read 6/6 with their habitual correction. Each participant's amplitude of accommodation, NRA and PRA, MEM retinoscopy, NPC, near heterophoria and near horizontal fusional vergence were measured before and after watching a movie on a smartphone to determine if there is a change in the accommodation and convergence system. In addition, a questionnaire for subjective symptoms was administered before and after the task. The smartphone was viewed continuously for a total duration of 30 minutes at a distance of 40cm. The data obtained was analyzed using the paired T-test in order to compare the mean between the AoA, NRA and PRA, MEM retinoscopy, NPC, NLP and NHFV before and after smartphone usage. The result revealed a significant change in the accommodation and convergence parameters after viewing the smartphone (p<0.05). Paired Ttest was used to analyze the pre and post-questionniare data in order to compare the observed subjective symptoms and this unveiled that the most common symptoms reported were dry eye, tired eye, headache and blurred vision, and the least reported symptoms were double vision, sore eye, pain behind the eye, Itchy eye and watery eye after the task.