INVITED REVIEW The association between digital screen time and myopia: A systematic review Carla Lanca 1 and Seang-Mei Saw 1,2,3 1 Singapore Eye Research Institute, 2 Saw Swee Hock School of Public Health, National University of Singapore, and 3 Duke-NUS Medical School, Singapore City, Singapore Citation information: Lanca C & Saw S-M. The association between digital screen time and myopia: A systematic review. Ophthalmic Physiol Opt 2020; 40: 216–229. https://doi.org/10.1111/opo.12657 Keywords: children, myopia, screen time Correspondence: Seang-Mei Saw E-mail address: ephssm@nus.edu.sg Received: 3 July 2019; In Revised form: 30 October 2019; Accepted: 9 November 2019 Author contributions: CL: involved in study conception; data acquisition, analysis and interpretation; drafting the manuscript. SMS: involved in study conception and design; data interpretation; critically revising the manu- script. Abstract Purpose: Digital screen time has been cited as a potential modifiable environmen- tal risk factor that can increase myopia risk. However, associations between screen time and myopia have not been consistently reported. Although myopia preva- lence increased before the massive use of digital devices in some countries, with the rise being influenced by education, there may be an added recent effect of screen time. The aim of this systematic review is to determine the association between screen time and the risk of developing (1) prevalent or incident myopia, or (2) the risk of myopia progression in children. Published manuscripts were identified in PubMed, ScienceDirect and the Cochrane Library, and citation lists were reviewed. Recent findings: Fifteen studies were included (nine cross-sectional and six cohort studies) with a total of 49 789 children aged between 3 and 19 years old. Seven studies found an association between screen time and myopia. The results showed mixed evidence with the more recent studies exposing a trend of association between hours spent by children using screens and myopia. Meta-analysis using a random-effects model was performed in five studies (n = 20 889) that reported odds ratio (OR). The I 2 statistics was used to assess heterogeneity. A pooled OR of 1.02 (95% CI: 0.96–1.08; p = 0.48) suggests that screen time is not associated with prevalent and incident myopia in this group of five studies. Summary: The results for screen time and myopia are mixed. Further studies with objective screen time measurements are necessary to assess evidence of an association between screen time and myopia. Introduction Myopia is a major contributor to the global burden of eye disease due to high prevalence, especially in East Asia. 1 In 2015, 10.0 million people were estimated to have visual impairment from Myopic Macular Degeneration, 3.3 mil- lion of whom were blind. 2 The high prevalence of myopia in East Asian cities is due to several risk factors, including environmental factors such as education, increased near work and less time spent outdoors. 3–8 In recent years, computers, smart phones and tablets have been argued to play a role in myopia development, and thus this is a current issue. Several studies have examined the individual relationship of digital screen time as a risk factor for myopia. However, consistent evidence of an association between screen time and myopia development is lacking. 9 Education and near work have played major roles in the rise in myopia rates even before the introduction of digital devices. 10–12 The secondary role of screen time should also be examined, although screen time cannot explain the epi- demic of myopia in East Asian countries such as Singapore, Taiwan, Korea or Japan, as the rise in myopia prevalence rates occurred several decades ago before screen devices were introduced. However, the recent rapid rise of screen time use may further add to the high myopia rates in Asia and worldwide, and this latest trend could be evaluated. © 2020 The Authors Ophthalmic & Physiological Optics © 2019 The College of Optometrists Ophthalmic & Physiological Optics 40 (2020) 216–229 216 Ophthalmic and Physiological Optics ISSN 0275-5408