1
Introduction

In the past four decades, tremendous increases in the prevalence of myopia (nearsightedness) have been reported worldwide. In the United States, myopia, which affected 25% of the population in 1971–1972, increased in prevalence to affect 42% by 2004 (Vitale et al., 2009). Equivalent figures for some Asian countries are as high as 88% currently (Xiang & Zou, 2020). Along with the overall rise in myopia prevalence, the prevalence of high myopia (in excess of – 5.00 diopters [D] myopia) has also climbed; high myopia is commonly associated with earlier onset and prolonged myopia progression. Myopia progression is defined as a clinically meaningful increase in the degree of existing myopia, that is, on the order of –0.50 D, a change sufficient to reduce visual acuity for objects seen at a distance (see Box 2-1 for an explanation of the term diopter).

If current trends continue, there will be 5 billion near-sighted individuals globally by 2050 (Holden et al., 2016). And while increased prevalence may be disconcerting, the negative effects of myopia on the eye, beyond distance blur without glasses, will also increase. As such, the goal of treating myopia is to reduce the risk of vision loss associated with myopia. The benefit of slowing down myopia growth by one diopter is associated with a 40% reduction in risk of myopic maculopathy (Bullimore & Brennan, 2019). While currently available treatments have not been able to slow myopia by more than 0.75 D in two years (Lawrenson et al., 2023), the preponderance of evidence suggests that both myopia and myopia progression should be treated. And, given the risk to ocular health in the myopic eye, these factors lend themselves to calling myopia a disease rather than a simple refractive error.

The National Academies of Sciences, Engineering, and Medicine appointed a committee to address four questions about myopia (see Box 1-1 for the full charge to the committee). This report was prepared by the appointed committee to address this charge. The topics covered in this report include the basic anatomical and physiological development of myopia; the environmental factors that might increase risk (such as near work) or offer protective effects (such as time outdoors); the inconsistent evidence around the effect of electronic devices; treatment options; screening tools and procedures; types of screening options/opportunities; diagnosis; treatment; public policy; and professional practice approaches to promote equitable and continued access to ocular healthcare for diagnosis and treatment.

The project was supported by the National Institutes of Health, specifically the National Eye Institute; the American Academy of Optometry; the American Optometric Association; Health Care Alliance for Patient Safety; the Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley; Johnson & Johnson Vision; Reality Labs Research; Research to Prevent Blindness; and the Warby Parker Impact Foundation.

COMMITTEE FORMATION

Conflict-of-interest concerns were salient in this consensus study due to the involvement of industry sponsors and the tight link between industry and basic science in the field of myopia remediation. While a strict prohibition on conflicts of interest was upheld, exceptions were made if deemed unavoidable and publicly disclosed by the National Academy of Sciences. One such exception was made for committee member Donald Mutti from The Ohio State University, whose expertise was deemed essential for addressing all aspects of the committee’s statement of task (see Appendix B for additional information about the disclosure of unavoidable conflict of interest).

COMMITTEE FOCUS AND PROCESS

Refractive errors arise when the eye shape hinders light from focusing properly on the retina. While its review encompassed various types of refractive errors, the committee’s strongest focus was on addressing myopia. It is crucial to note that all degrees of myopia are associated with a heightened risk of serious eye conditions and morbidities, such as retinal detachment, myopic maculopathy, cataracts, and glaucoma (Haarman et al., 2020). Moreover, this risk escalates with the severity of myopia, consequently increasing the likelihood of visual impairment.

To address all components of its charge, the committee determined it would need to collect information about the factors that contribute to the onset and progression of myopia, what is known about myopia prevalence shifts in the United States and worldwide, myopia pathogenesis, options for diagnosing and treating myopia, and current vision screening and treatment practices with an emphasis on disparities. The committee was also tasked to describe “unique characteristics of electronic device contribution to the rapid increase in myopia.” Due to the inconsistent evidence regarding a correlation between the use of electronic devices and myopia incidence, the committee highlighted the need for additional research to better understand this relationship.

Also, the committee underscores the separate influences genetics and environmental factors may have on the onset and progression of myopia, as these factors may lead to potentially different paths of management. Genetics may require less prevention and more management, as compared to the manipulation of environmental factors that could be minimized or altered by introducing likely public health interventions.

The committee identified areas requiring additional expertise, invited supplementary experts to present data, and commissioned papers on selected topics. The committee conducted an intensive literature review and convened a public workshop,¹ which allowed members to learn more about a range of topics related to its statement of task. During the public workshop, experts addressed the rise in myopia, exploring possible contributors and investigating screening practices, policies, and programs. Myopia experts and those adjacent to the field relayed information that helped inform committee deliberations, including presentations on novel international initiatives in Australia, Singapore, and Taiwan. Implications for the development and progression of myopia, and practices, policies, and programs aimed at identifying and reducing myopia in the United States, were also discussed.

Finally, the committee commissioned papers to delve more deeply into five key topics: animal models, genetic versus environmental factors, access to care, treatment of childhood myopia, and the optical and visual diet. Each commissioned paper enhanced the committee’s understanding of key issues in this report. They are:

• Animal Models of Myopia: Lessons for the Understanding of Human Myopia (Bullimore, 2024);
• Perspectives on Genetic and Environmental Factors in Myopia, Its Prediction, and the Future Direction of Research (Hammond & Williams, 2024);

___________________

¹ The workshop recording is available on the project website: https://www.nationalacademies.org/event/41360_12-2023_workshop-on-the-rise-in-myopia-exploring-possible-contributors-and-investigating-screening-practices-policies-and-programs

• Access to Myopia Care—A Scoping Review (Harwood et al., 2024);
• Treatment of Childhood Myopia (Khanal et al., 2024); and
• Optical and Visual Diet in Myopia (Marcos, 2024).

The committee also reviewed literature related to the statement of task that was addressed in several other reports published by the National Academies, including but not limited to: Reproducibility and Replicability in Science (National Academies, 2019); Making Eye Health a Population Health Imperative: Vision for Tomorrow (National Academies, 2016); Relieving Pain in America: A Blueprint for Transforming Prevention, Care, Education, and Research (Institute of Medicine, 2011); Reports of the Committee on Vision: 1947–1990 (NRC, 1990); and Myopia: Prevalence and Progression (NRC, 1989).

ORGANIZATION OF THE REPORT

With the above guidance in mind, the committee developed a report that addresses the statement of task in the following format:

• A primer on the basic nature of myopia and the human eye (Chapter 2)
• An overview of myopia prevalence data and emerging patterns (Chapter 3)
• Assessment and diagnostic technologies used in screenings and evaluations of myopia (Chapter 4)
• The current state of understanding the genetic and environmental contributions to the onset and progression of myopia (Chapter 5)
• Pathogenesis: Underlying ocular mechanisms responsible for myopia (Chapter 6)
• Treatment options available to individuals with myopia (Chapter 7), and
• Barriers to identifying and treating myopia (Chapter 8).

Chapters 3 through 8 present recommendations tailored to various stakeholders in research, policy, and related domains to advance our comprehension of myopia. Chapter 9 consolidates and organizes these recommendations according to the type of stakeholder, such as researchers/practitioners, policymakers, developers of assessment and diagnostic technologies, and industry leaders. Some chapters will be easier to comprehend for readers with more technical knowledge, but all chapters are written to introduce and conclude in a manner accessible to the breadth of readership. Readers of the entire document will find some repetition, as the Committee anticipates that not everyone will read the entire document and each chapter is written to be self-contained. This categorization aims to provide a framework for guiding interdisciplinary research on myopia, emphasizing the importance of collaboration across different fields.

For the benefit of any reader unfamiliar with the more specialized terms used in the fields of optometry, ophthalmology, and vision science generally, a glossary of terms related to refractive errors (specifically myopia) as well as research related to other subjects discussed in this report is provided in Appendix C.

REFERENCES