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  • Excessive Smartphone Use and Myopia in Teens

    By Lynda Seminara
    Selected by Stephen D. McLeod, MD
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    Journal Highlights

    Ophthalmology, December 2021

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    How much of a relationship is there between smartphone use and myopia prevalence? Enthoven et al. studied the use of smartphones among teen­agers and found that refractive errors were more common when smartphone sessions lasted 20 minutes or longer, particularly for those teens who spent less time outdoors.

    For this cross-sectional study, teens (12-16 years) were recruited from six Dutch secondary schools and from the Generation R study. A myopia app was installed on their phones; the app calculated phone time in hours per day and face-to-screen distance for a five-week period. On-screen episodes lasting 20 minutes without a break were documented and were deemed “continuous use.” Twice weekly, the app prompted participants to log the time they had spent outdoors. Ocular biometry was performed, and cyclo­plegic refractive error was measured. Linear mixed models were applied, with overall smartphone use, continu­ous use, and face-to-screen distance as determinants, and spherical equivalent of refraction (SER) and the ratio of ax­ial length to corneal radius (AL:CR) as outcome measures. Findings were strat­ified by the level of outdoor exposure.

    Valid smartphone data and eye measurements were available for 272 enrollees (average age, 13.7 years). The overall my­opia prevalence was 18.9%. On school days, mean daily smartphone use (± standard deviation) was 3.71 ± 1.70 hours. The association with AL:CR was minimally significant, but the association with SER was not. The mean number of continuous-use sessions (20 minutes without a break) per day was 6.42 ± 4.36, which correlat­ed significantly with SER and AL:CR. When stratified by time spent outdoors, continuous use was significant for those teens with low outdoor exposure. Face-to-screen distance and smartphone use on weekends had no significant relationship to SER or AL:CR.

    The findings suggest that the teens in this study spend nearly four hours a day on their smartphones and that un­interrupted 20-minute sessions increase the risk of myopia.

    The original article can be found here.