Welcome to the third “Myopia Mythbusters” column. In each, April Jasper, O.D., presents a myth, and Mark Bullimore, MCOptom, Ph.D., tries to bust it (similar to our webinar series). The myths originate from questions posed by eye care professionals and are relevant to myopia management.

This month’s myth: Digital devices are responsible for the myopia pandemic.

THE FACTS

It’s a popular narrative that digital devices are responsible for the increasing prevalence of myopia, but the data do not support this assertion.

For example, a recent systematic review of large-scale studies (i.e., 15 studies [nine cross-sectional and six cohort studies] with a total of 49,789 children) reveals “the rise in myopia prevalence rates in East Asian countries, such as Japan, occurred several decades before screen devices were introduced.”¹

Additionally, although the personal computer arrived in the early 1980s, children were developing myopia at epidemic rates in Hong Kong, Taiwan and Singapore in the 1970s.²

The study’s researchers conclude that the pooled odds ratio of 1.02 (95% confidence interval: 0.96–1.08; p = 0.48) shows that screen time is not associated with the prevalence or incidence of myopia.¹ Note that the odds ratio is close to 1, and the confidence interval includes 1, indicating no significant relationship.

The researchers also note no recent spike in myopia prevalence associated with the proliferation of digital devices, but rather a stable and gradual slow trajectory in the last years. In some regions, e.g., Hong Kong, myopia prevalence has remained constant over two decades, despite the changes in the education system and children’s learning behavior.

Something else to consider: Evidence within studies can be contradictory. For instance, in a recent study of 418 Irish schoolchildren, myopic children used almost double the amount of smartphone data per day vs. non-myopic children, but smartphone usage time was not significantly different between the two groups.³

In contrast, there is a strong relationship between more time spent outdoors and less myopia, making it the most important modifiable risk factor for myopia onset.⁴ Also, the World Health Organization guidelines to restrict sedentary screen time for children younger than age 5 are based on evidence that it has a negative impact on children’s sleep and physical activity, among other health behaviors.

THE SOLUTION

Let’s educate parents about how more time spent outdoors is protective in the pre-myopic child.

TAKE-HOME MESSAGES

Less screen time and more time outdoors are good for a child’s sleep patterns, weight and cardiovascular health. The association between screen time and myopia is tenuous at best. This will be a huge relief to most parents who have children required to spend significant time on digital devices. Remind parents and patients of the importance of outdoor time, as it is protective in that early, pre-myopic child. OM

References 

1. Lanca C, Saw SM. The association between digital screen time and myopia: A systematic review. Ophthalmic Physiol Opt. 2020;40:216-29. doi: 10.1111/opo.12657.
2. Morgan IG, French AN, Ashby RS, et al. The epidemics of myopia: aetiology and prevention. Prog Retin Eye Res. 2018;62:134-49. doi: 10.1016/j.preteyeres.2017.09.004.
3. McCrann S, Loughman J, Butler JS, Paudel N, Flitcroft DI. Smartphone use as a possible risk factor for myopia. Clin Exp Optom. 2021;104(1):35-41. doi: 10.1111/cxo.13092.
4. Deng L, Pang Y. Effect of Outdoor Activities in Myopia Control: Meta-analysis of Clinical Studies. Optom Vis Sci. 2019;96:276-82. doi: 10.1097/OPX.0000000000001357.
 

DR. BULLIMORE writes about myopia and other topics, is an adjunct professor at the University of Houston, a consultant for Alcon Research, Allergan, CooperVision, Essilor, Eyenovia, Genentech, Johnson & Johnson Vision, Novartis and Presbia and owner of Ridgevue Publishing, Ridgevue Technologies and Ridgevue Vision.

DR. JASPER practices in West Palm Beach, Fla. She is an American Academy of Optometry fellow and is chief optometric editor of Optometric Management. Email her at april.jasper@pentavisionmedia.com.