This article was originally published in a sponsored newsletter.

The increase in the worldwide prevalence of myopia¹ points toward today’s modern environment (i.e., near viewing, growing use of electronic devices, and/or time indoors). The exact mechanism of myopia progression remains elusive, primarily because of its multifactorial origin.² And the risk factors appear correlated. For instance, increased near work and indoor time correlate with reduced outdoor exposure, both of which are hypothesized to be associated risk factors for myopia progression.^3-5

Other associated factors include the presence of accommodative lag during near work, which creates hyperopic retinal defocus or “grow signal” for myopia progression.^5-7 On the other hand, the protective myopia progression effect of outdoor time is partly explained by enhanced depth of focus due to pupil miosis, overall increased light exposure,⁴increased exposure to short wavelength components of spectrum (e.g., violet and blue light),⁸ release of retinal dopamine,⁹ and increased exposure to high spatial frequencies when outdoors.¹⁰

Controlled laboratory investigations in animal models^6,11 as well as humans^5,8,12 performed by isolation of these factors report connection to myopia in different ways.⁷ For instance, near work at close reading distance (< 30cm) and continuous reading (> 30 minutes) independently increased the odds of having myopia in a sample of Australian children.⁵ It is now widely acknowledged that prolonged near work activities, inaccurate accommodation, spending more time indoors or less time outdoors, and other factors may all impact the development and progression of myopia.

Recent technological advancements have led to modern electronic devices that are now widely used in daily activities, and the usage is reported to start from an early age.¹³ Children and young adults are spending a lot of time using these devices,^13,14 which has further increased their near work activities and subsequent time spent indoors. The added near work—because of increased electronic device usage—has thus emerged as a growing concern.

Recent research aimed to explore the potential link between near work, accommodation, and myopia under modern viewing conditions.¹⁵ Specifically, the study evaluated accommodative behavior of non-myopic and myopic subjects ranging between 18 to 25 years of age with prolonged viewing of targets at near (25cm) on a commonly used electronic device (i.e., a smart phone). The researchers also examined the participants’ post-task accommodative adaptation under two conditions: closed-loop conditions to explore near-work induced transient myopia (NITM) and open-loop conditions to evaluate adaptation of tonic accommodation (ATA).

Initial findings from seven subjects (two non-myopes and five myopes) showed comparatively similar accommodative behavior among the two refractive group of subjects in both the NITM and ATA measurement sessions. Under prolonged viewing (20 minutes) of electronic devices at near, the accommodative behavior of young adults showed minimal change and the observed accommodative lags were mostly < 1.00D throughout the duration of the near task. Next, the authors plan to conduct a more robust analysis of their dynamic accommodative behavior including data from all subjects.

1. Holden BA, Fricke TR, Wilson DA, et al. Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050. Ophthalmology. 2016 May;123:1036-1042.

2. Morgan IG, Rose KA. Myopia: is the nature-nurture debate finally over? Clin Exp Optom. 2019 Jan;102:3-17.

3. Saw SM, Chua WH, Hong CY, et al. Nearwork in early-onset myopia. Invest Ophthalmol Vis Sci. 2002 Feb;43:332-339.

4. Xiong S, Sankaridurg P, Naduvilath T, et al. Time spent in outdoor activities in relation to myopia prevention and control: a meta-analysis and systematic review. Acta Ophthalmol. 2017 Sep;95:551-566.

5. Ip JM, Saw SM, Rose KA, et al. Role of near work in myopia: findings in a sample of Australian school children. Investig Opthalmology Vis Sci. 2008 Jul;49:2903.

6. Smith III EL, Hung LF. The role of optical defocus in regulating refractive development in infant monkeys. Vision Res. 1999 Apr;39:1415-1435.

7. Wojciechowski R. Nature and nurture: the complex genetics of myopia and refractive error. Clin Genet. 2011 Apr;79:301-320.

8. Torii H, Kurihara T, Seko Y, et al. Violet Light Exposure Can Be a Preventive Strategy Against Myopia Progression. EBioMedicine. 2017 Feb;15:210-219.

9. Zhou X, Pardue MT, Iuvone PM, Qu J. Dopamine signaling and myopia development: What are the key challenges. Prog Retin Eye Res. 2017 Nov;61:60-71.

10. Flitcroft DI, Harb EN, Wildsoet CF. The Spatial Frequency Content of Urban and Indoor Environments as a Potential Risk Factor for Myopia Development. Invest Ophthalmol Vis Sci. 2020 Sep 1;61:42.

11. Smith EL 3rd. Prentice award lecture 2010: A case for peripheral optical treatment strategies for myopia. Optom Vis Sci. 2011 Sep;88:1029-1044.

12. Rose KA, Morgan IG, Ip J, et al. Outdoor activity reduces the prevalence of myopia in children. Ophthalmology. 2008 Aug;115:1279-1285.

13. Common Sense Media. The Common Sense Census: Media Use by Kids Age Zero to Eight, 2020. 2020 Nov 17. Available at commonsensemedia.org/research/the-common-sense-census-media-use-by-kids-age-zero-to-eight-2020. Accessed Aug. 17, 2023.

14. Common Sense Media. The Common Sense Census: Media Use by Tweens and Teens, 2021. 2021 Mar 9. Available at commonsensemedia.org/research/the-common-sense-census-media-use-by-tweens-and-teens-2021. Accessed Aug. 17, 2023.

15. Sah RP, Meyer D, Murthy N, Kollbaum PS. Accomodative behavior in young eyes with prolonged viewing of electronic devices. Invest Ophthalmol Vis Sci. 2023 Jun;64:4938.