Abstract
The global burden of myopia continues to expand, and the prevalence of myopia in East Asian populations is of particular concern. With the substantial increase in screen-based electronic devices, screen time has emerged as a potential risk factor. This review examined the relationship between screen viewing duration and myopia risk and public health strategies to reduce screen exposure among children. We conducted an evidence-based review of only meta-analyses investigating screen time and myopia association, searching PubMed from inception to January 20, 2025. Four of the six meta-analyses reviewed supported an association between prolonged screen use (> 2 or 3 hours/day) and increased myopia risk. However, methodological limitations include the predominance of cross-sectional study designs, self-reported screen time measurements, and the lack of cycloplegic refraction in some studies within the meta-analyses. Current public health strategies focus mainly on banning mobile phones in schools and limiting screen time. Technology-based solutions, such as anti-addiction systems, support and complement these strategies. Healthcare providers play a crucial role in assessing screen time patterns in children and providing evidence-based recommendations. Future studies should employ objective screen time measurements, conduct longitudinal analyses with cycloplegic refraction, and evaluate the effectiveness of screen time interventions in myopia prevention through randomized controlled trials. In addition, examining the combined effects of traditional near-work activities and screen time may provide more comprehensive insights into myopia risk factors.
1
Introduction
Myopia, the most common refractive error worldwide, has seen a marked increase in prevalence in recent decades, particularly in East Asia. The World Health Organization (WHO) estimates that nearly 52 % of the global population will be affected by myopia by 2050. Rapidly evolving environmental and lifestyle factors have undoubtedly played a key role in its global rise. These factors include reduced time spent outdoors and prolonged near-work activities in daily life, such as excessive screen time or reading and writing.
1.1
The worldwide introduction and history of screen time
Screen time is a form of near work and may be linked to myopia, especially with the rapid proliferation of digital devices. Historically, desktop computers were introduced in offices in the 1970s, followed by personal computers in the late 1970s to the 1990s. The advent of the World Wide Web in 1993 further increased screen dependency. With the introduction of smartphones in 2007 and tablets in 2010, digital devices quickly became ubiquitous by the mid-2010s ( Fig. 1 ), significantly altering how children and adolescents engage in near-work activities.
The traditional forms of near-work, paper-based reading and writing activities have been partially replaced by screen-based activities. Thus, there may be a slight reduction in reading or writing time but an increase in screen time and possibly an increase in total near-work time. Twenge et al.’s study among 1,021,209 U.S. adolescents from 1976 to 2016 found that reading of books or magazines among 16- to 17-year-olds dropped from 60 % in the late 1970s to 16 % in 2016, while digital media use increased from 52 % in the late 2000s to 82 % in 2016. International studies by Harvey et al. (2013) and Bucksch et al. (2020) documented consistent upward trends in screen time among adolescents across multiple countries. A national study by the Kaiser Family Foundation of over 2,000 students aged 8–18 in the United States showed a significant increase in non-educational screen time – daily computer use rose from 27 minutes in 1999 to 89 minutes in 2009 ( P < 0.05) and video game use increased from 26 to 73 minutes over the same period ( P < 0.05). These changes have generated research interest in the potential association of screen exposure with myopia.
1.2
Rise in myopia prevalence over the decades, even before the advent of digital devices
The prevalence of myopia in East Asia increased in the late 1970s, even before the advent of digital electronic devices ( Fig. 2 ). In Singapore, the prevalence of myopia using cycloplegic refraction was approximately 40 % among 2,943 Chinese adults born in the late 1950s and early 1960s in the Singapore Cohort of Risk factors for Myopia (SCORM), while this prevalence exceeded 70 % in 1074 Chinese adults born in the 1970s in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort. Notably, the childhood of these cohorts (1980–2000) preceded the era of widespread use of personal computers. Similarly, in Japan, eye examinations conducted between 1984 and 1996 found that myopia prevalence in 17-year-olds among 9,420 lower and upper secondary students rose from 49.3 % in 1984 to 65.6 % in 1996 (non-cycloplegic refraction) during the early stages of public internet access. Lin et al. analyzed the trend of myopia prevalence in children in Taiwan from 5 nationwide surveys of ocular refraction conducted between 1983 and 2000 and found that the myopia rate in 18-year-old students (measured by cycloplegic autorefraction) rose from 75 % (n = 574) in 1983 to 84 % (n = 790) in 2000. While East Asian countries have higher myopia prevalence and more significant increases, rising trends have also been documented in other regions globally.
This review aims to conduct an evidence-based review of only meta-analyses of screen time and myopia, as well as summarize public health recommendations to restrict screen time in children.
2
Screen time and myopia
The association between screen time and myopia is a controversial topic. Several epidemiological studies have examined this relationship, but the results have been mixed. Harrington and O’Dwyer (2023) reported that among 723 Irish children aged 6–7 years, screen time > 2 hours per day was significantly associated with premyopia measured by cycloplegic refraction (spherical equivalent (SE) > -0.50D to ≤ + 0.75D; odds ratio (OR) = 2.40, 95 % CI: 1.50–3.70, P < 0.001) and myopia (SE ≤ −0.50D; OR = 10.9, 95 % CI: 4.40–27.20, P = 0.01). A cross-sectional study in 2022 in Taiwan involving 23,930 preschool children aged 5–6 years found that screen time ≥ 1 hour per weekday significantly increased the prevalence of premyopia (SE > −0.50D to ≤ + 0.75D; OR 1.10 [95 % CI 1.04–1.17]; P = 0.001) and myopia (SE ≤ −0.50D; OR 1.20 [95 % CI 1.09–1.32]; P < 0.001). In contrast, Berticat et al.’s (2020) analysis of cross-sectional data from 264 children attending clinics in France between 2017 and 2018 revealed no direct association between the duration of digital devices (computers, mobile phones, tablets, video games, etc.) and myopia (OR = 2.32, [95 % CI 0.89–6.05]; P > 0.05). The study defined myopia as SE < 0 D, but the authors stated that using SE ≤ -0.5 D would not affect the results. However, selection bias may exist as the children were recruited from clinics, not the community.
2.1
Evidence-based review of meta-analyses of screen time and myopia
Several meta-analyses of original articles evaluating screen time and myopia have been published in the past few years and we have conducted an evidence-based review of these meta-analyses.
We searched the PubMed database for meta-analyses examining the relationship between screen time and myopia from database inception through January 20, 2025. The search terms included: (screen time [Mesh] OR digital device OR computer OR tablet OR smartphone OR handheld device) AND (myopia [Mesh] OR refractive error OR near-sightedness). The literature search and screening process is illustrated in Fig. 3 . This initial search yielded 3,279 articles. After applying filters to identify meta-analyses and systematic reviews with meta-analyses, 39 articles were selected for further evaluation. The inclusion criteria were as follows: (1) meta-analyses or systematic reviews with meta-analyses; (2) reported effect estimates (e.g. pooled odds ratios or risk ratios); (3) published in English. After assessment against these criteria, six meta-analyses/systematic reviews met the inclusion criteria and are summarized in Table 1 .
| Author(s) | Year | Year studies published | Number of studies in the meta-analyses (sample size) | Study design (number of studies) | Findings |
|---|---|---|---|---|---|
| Zong et al. | 2024 | 2010–2023 | 19 studies (n = 102,360) | Cohort (4); Cross-sectional (15) | Screen time in children and adolescents was associated with myopia (pooled OR = 2.24, 95 % CI: [1.47–3.42], I² = 90 % for cross-sectional studies; pooled OR = 2.39, 95 % CI: [2.07–2.76], I² = 0 % for cohort studies). Continuous exposure in cohort studies showed a 7 % increase in the odds of myopia per additional hour of screen time per day (pooled OR = 1.07, 95 % CI: [1.01–1.13]). |
| Zhang et al. | 2022 | 2009, 2020 | 2 studies (n = 10,805) | Cross-sectional (2) | High duration of screen time (>2 hours/day) among school-aged children and adolescents in China was associated with myopia (pooled OR = 1.71, 95 % CI: [1.18–2.47]; I² = 79.3 %). |
| Yang et al. | 2022 | 2021 | 3 studies (n = 2,022) | Cohort (3) | Increased digital screen use was significantly associated with myopia progression in children during the COVID−19 pandemic (pooled OR = 3.36, 95 % CI: [1.75–4.97]; I² = 99 %). |
| Foreman et al. | 2021 | 2015–2020 | 11 studies (n = 40,048) | Cohort (3); Cross-sectional (8) | Increased smart device screen time was associated with myopia, with a pooled OR of 1.26 (95 % CI: [1.00–1.60]; I² = 77 %). The combination of smart devices and computer use showed a positive association (OR = 1.77, 95 % CI: [1.28–2.45]; I² = 87 %). |
| Wang et al. | 2020 | 2019–2020 | 5 studies (n = 23,939) | Cross-sectional (5) | Smartphone time was not significantly associated with myopia (pooled OR = 1.00; 95 % CI: [0.95–1.05]; I² = 71 %). |
| Lanca and Saw | 2020 | 2007–2016 | 5 studies (n = 20,889) | Cohort (1); Cross-sectional (4) | Screen time was not significantly associated with myopia (pooled OR = 1.02, 95 % CI: [0.96–1.08], P = 0.48; I² = 0 %). |
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