Excessive screen time (>2 hours per day) may be associated with increased myopic spherical equivalent refraction (SER), a higher myopia risk, premyopia, and increased weight and body mass index (BMI) among children aged 6 to 7 years, according to a study published in Ophthalmic and Physiological Optics.
Investigators included 723 children (mean age 7.08 years; 51.8% boys) in a stratified random sample and performed cycloplegic refraction, ocular biometry, and height and weight measurements. Participants’ caretakers reported the amount of time spent using screens and performing near reading and writing tasks using a questionnaire. The research team examined associations between screen time and SER, ocular biometric measurements, and BMI.
Caretakers most commonly reported screen times of 1 to 2 hours per day (49.2%), followed by less than 1 hour (30.8%), 2 to 4 hours (15.5%), and more than 4 hours (3.9%). Children who spent more time using screens tended to have myopia. Among participants with more than 4 hours of daily screen time, 33.3% had myopia (≤-0.50 diopters [D]) and 2.7% did not have myopia. Reported screen time of 2 to 4 hours, 1 to 2 hours, and less than 1 hour revealed myopia prevalences of 40.7%, 11.1%, and 14.8%, respectively. Linear regression analysis showed that more than 2 hours of screen time was significantly associated with increased weight (β, 1.61; P <.001) and BMI (β, 0.92; P <.001), ratio of axial length to mean corneal radius (β, 0.04; P <.001), refractive astigmatism (β, -0.12; P <.05), and spherical equivalent refraction (β, -0.56; P <.001). Daily screen time of more than 2 hours was associated with myopia (odds ratio [OR], 10.9; 95% CI, 4.4–27.2; P =.01) and premyopia (OR, 2.4; 95% CI, 1.5–3.7; P <.001), the report shows.
Participants’ SER was predicted (adjusted R2, 0.069) by ethnicity (β, 0.72; P <.001), maternal myopia (β, -0.25; P <.05), age (β, -0.32; P <.01) and daily screen time (β, -0.37; P <.01). The ratio of axial length to corneal radius was predicted (adjusted R2, 0.069) by daily screen time (β, 0.03; P <.001), age (β, 0.02; P <.01), paternal myopia (β, 0.02; P <.05), maternal myopia (β, 0.01; P <.05), and ethnicity (β, -0.03; P <.01). BMI was predicted (adjusted R2, 0.079) by daily screen time exposure (β, 0.88; P <.001), maternal myopia (β, -0.39; P <.05), and living environment (urban vs rural; β, -0.42; P <.05).
“Due to the ubiquity of screen media, culturally sensitive education to support screen-limiting strategies is vital when addressing myopia management,” according to the study authors.
Failure to objectively measure screen time is an acknowledged limitation to the research.
Harrington S, O’Dwyer V. The association between time spent on screens and reading with myopia, premyopia and ocular biometric and anthropometric measures in 6- to 7-year-old schoolchildren in Ireland. Ophthalmic Physiol Opt. Published online February 26, 2023. doi:10.1111/opo.13116