Binocular vision findings in normally-sighted school aged children who used digital devices.

Purpose: To determine the binocular vision status in normally-sighted school aged children who used digital devices.

Methods: A cross-sectional study was conducted at B.P. Koirala Lions Center for Ophthalmic Studies, Kathmandu, Nepal for a duration of one year. One hundred and eighty school aged children (71 female and 109 male) aged 7 to 17 years were included in the study. All the children underwent detailed ophthalmic and binocular vision examinations. The duration of the use of digital devices by the children were asked to either the parents or guardians present at the time of the study. The study participants were divided into two groups: children who used digital devices for the last six months (users group) and those who hadn't used digital devices for the last six months (non users group). The users group was again divided into two subgroups: children who used digital devices for less than 3 hours per day and a day per week (low digital device users subgroup) and children who used digital devices for more than 3 hours per day and all days in a week (high digital device users subgroup).

Results: Accommodative amplitudes, accommodative facility, and positive fusional vergence for both near and distance were significantly reduced in the high digital device users group than in the low digital device users subgroup (p <0.01). Stereo acuity, near point of convergence, and negative fusional vergences for both near and distance were not statistically significantly different between the two subgroups. Prevalence of accommodative and vergence anomalies (except convergence insufficiency) was more in the high digital device users subgroup than in the low digital device users subgroup (p<0.01).

Conclusions: Children who used digital devices for a significantly greater amount of time had significantly reduced amplitudes of accommodation, accommodative facility, and positive fusional vergence both at near and distance.