Understanding smartphone overuse and its impact on the ocular system can help the growing population of users, especially children, manage their devices in a healthier way. A systematic review of 14 studies revealed a significant association between smartphone overuse and visual impairment. However, the cross-sectional studies showed negative, but not statistically significant, associations between smartphone overuse and myopia, blurred vision and poor vision. Still, the adverse effects were more apparent in children than young adults.

The review examined 10 cross-sectional studies and four controlled trials, which included a total of 27,110 patients ranging in age from 9.5 to 26.

From the cross-sectional studies, the pooled odds ratio of 1.05 suggested that smartphone overuse was not significantly associated with myopia, poor vision or blurred vision; however, these visual impairments were more apparent in children (1.06) than young adults (0.91).

The controlled studies revealed that patients who overused smartphones displayed worse visual function scores. The pooled effect size was 0.76, which was statistically significant.

The researchers noted that most of the studies included in their systematic review were from Asia, which had higher prevalence rates of visual impairment even before digital devices were introduced.

Nevertheless, these results suggest that regulating device usage and restricting prolonged smartphone use may prevent adverse ocular and visual symptoms, especially in younger patients. The researchers recommend further research on the patterns of use, with longer follow-up on the longitudinal associations, to better inform detailed guidelines and recommendations for smartphone use in children and young adults.

Wang J, Li M, Zhu D, et al. Smartphone overuse and visual impairment in children and young adults: systematic review and meta-analysis. J Med Internet Res. 2020;22(12):e21923.