Nearsightedness Has Become a Global Health Issue
In 350 B.C.E. Aristotle noted that some people went about their days with what he called “short sight.” People with this condition, he found, would habitually narrow their eyelids to focus their vision—an observation widely credited as the first attempt at defining nearsightedness, or myopia. More than two millennia later, health officials are paying new attention to this old condition for a startling reason: myopia has reached epidemic levels worldwide.Myopia’s prevalence has dramatically increased in recent decades, now affecting as much as 88 percent of the population in some Asian countries. Although it seems most acute in Asian cities, myopia’s growing prevalence is by no means an exclusively regional trend. By 2050, according to one estimate, five billion people—half the world’s population—will be nearsighted. The U.S., which has been less diligent than some other countries in tracking myopia cases, saw a jump in prevalence from 25 percent of people aged 12 to 54 in the early 1970s to 42 percent in the early 2000s, according to the last major national survey of the condition.These statistics matter because myopia is a leading cause of visual impairment, and it can precipitate serious diagnoses that range from detached retinas to glaucoma.On supporting science journalismIf you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.A search is now underway for tangible measures to stem this rising tide. An expert panel from the National Academies of Sciences, Engineering and Medicine (NASEM) released a report in September entitled Myopia: Causes, Prevention, and Treatment of an Increasingly Common Disease. It lays out a series of recommendations, one of which calls for the Centers for Medicare & Medicaid Services to reclassify myopia as a disease that necessitates a medical diagnosis—a step that would encourage federal and state agencies, along with professional associations, to devote resources to reversing the situation. Notably, the committee also recommended that children spend one to two hours outdoors each day.Terri L. Young, co-chair of the NASEM committee that produced the report and chair of the department of ophthalmology and visual sciences at the University of Wisconsin–Madison, talked with Scientific American about the implications of the myopia epidemic for people with myopia and policymakers.[An edited transcript of the interview follows.]I’d like to begin with the most basic of basics. Could you define what myopia, or nearsightedness, is?I’ll start off with what a person with myopia experiences. Myopia is a condition in which an individual sees an object up close clearly but cannot see it clearly at a distance without optical correction. They have natural blurred vision at a distance.Optically, there is a detailed definition that involves the very basics of how we see. Scattered light rays that enter the eye pass through multiple ocular components that reduce the scatter to focus the rays onto the retina, which converts the light into an electrical signal that is transferred through the optic nerve. The optic nerve is similar to a telephone cable that connects the eye to the occipital cortex at the very back of the brain, where what is viewed is then processed and interpreted.The focus of those wavelengths that enter the eye and travel through all its optical components needs to coincide on the retina. In the case of nearsightedness, or myopia, the focus of the light occurs in front of the retina.Myopia seems to be getting more attention lately, both in the U.S. and internationally. Why is that?Myopia prevalence rates are at epidemic levels, especially in urban Asian communities, where in recent times upward of 80 to 90 percent of young individuals have developed myopia. There are large, government-sponsored myopia research institutes in many parts of Asia, including Taiwan, Singapore, China, Hong Kong and Japan.Take Singapore, for example. All young men there are required to perform [two years] of military service after completing high school. Many of these military conscripts, and in particular the ones who are being prepared to go into battle or fly fighter planes, often need glasses or other corrective means for their myopia to fulfill those functions, causing concern for national security.And what about in the U.S.?It’s now certainly an issue in the U.S. as well. Research on myopia is conducted primarily in ophthalmologic and optometric training and research academic programs. But it hasn’t garnered, for whatever reasons, the same sense of urgency and funding as is the case for other parts of the world.In the U.S., we don’t have good prevalence data for myopia and other refractive errors, such as astigmatism and hyperopia [farsightedness]. Health care in this country is so varied in terms of everything from access to dissemination of vision care; because we don’t have a nationalized health system, we also don’t have a national database to provide standardized tracking and reporting.Aren’t there already simple ways to deal with myopia, such as getting a new prescription for glasses? Why is it perceived as becoming a global health problem?Myopia correction is not just an inconvenience of glasses or contact lenses. It predisposes a person to other eye conditions that can lead to blindness. Higher degrees of myopia are associated with eye conditions: premature cataracts, glaucoma, retinal tears and detachments and myopic macular degeneration.What’s happened in Asian communities is that the baseline level of refraction, the deflection of wavelengths as they pass through the eye, is trending toward nearsightedness. This shift is reflected in more individuals with high-grade myopia, with its increased ocular risks, as I described earlier. So instead of that group reflecting 3 to 5 percent of myopic individuals, it’s risen to 10 percent or more.Access to quality vision care, with proper and standardized dissemination for all children, is a major issue in [the U.S.] There are many children who don’t have steady access to care and the opportunity for continued changes in spectacle correction as they grow. If they can’t see, they can’t learn. If they don’t learn, they may get discouraged. If they get discouraged, they tend to act out or to not perform well in school—which has lifelong educational, vocational and economic impacts.Is there some idea why this myopia epidemic is happening?Nowadays, children are indoors more often, and they’re not getting as much outdoor play. Outdoor light enables the visual system to process a variety of spectral wavelengths of light for a certain duration of time, and that affects normal eye development and growth. Our report reaffirms what has been in the scientific literature for more than 15 years: increased childhood outdoor time appears to be protective for myopia onset and development.In urban Asia, education is highly regarded, and children undergo indoor schooling for relatively more hours per day—routinely with additional tutorial sessions on evenings and weekends. In Singapore, for example, there are fewer green spaces, and living situations are generally more vertical because of limited land mass. There are fewer nonclassroom hours and places for children to go outside to view the horizon for extended periods of time. That’s becoming more of the case in the urban U.S. as well.What does being outside do to promote healthy eyes?There are different and varied light wavelengths that enter the eye from outdoor versus indoor exposures. And there are differences in luminance—higher-intensity versus lower-intensity light levels. In the report, there is a lengthy discussion on what is called the “visual diet”—the environmental factors affecting the myopic eye—and there is a consensus that more research is needed.What about the role of electronic devices in promoting myopia?That’s certainly a trend that has exponentially grown in activity and use in our younger generations. I am a pediatric ophthalmologist. I see two- or three-year old children in my clinic who are comfortably playing with cell phones. This close-up activity is generally indoors. The limited research findings regarding electronic device impact on myopia development are inconclusive, however. Reflected in our report, studies could not support unequivocal evidence that using digital devices, especially electronic small devices, is an influencer for this shift toward myopia.What measures have countries implemented to try preventing or correcting myopia in young people?The Singapore Ministry of Health instituted outdoor playtime or recess during school hours. There are now programs in China and in Taiwan where classroom settings have been altered with the use of glass walls or colored light bulb use to increase outdoor daylight exposure. Children are undergoing treatment with atropine eye drops, which in some reports diminishes the shift toward myopia over time in the school-age years. The effect of the drops is not curative, however, and there are concerns regarding unknown long-term effects because we don’t quite understand the specific biochemical actions of atropine. Diagnosed children are also prescribed multifocal contact lenses or eyeglasses [progressive lenses that have different prescription zones to correct vision at different distances].One of the main findings of the report that you co-chaired is the recommendation that myopia be classified as a disease. Can you explain why the consensus of the panel felt that was important?The issue needs escalation to a recognized disease category to underscore its short- and long-term visual health consequences, and to attract attention and funding dollars on multiple and varied fronts for effective screening, treatment, prevention and research study.It takes a multipronged team to elevate this issue. That groundswell would have to come from parents, educators and educator societies, local to national health care systems, local to national policymakers, public health experts, researchers, funding agencies, insurance companies, etcetera. All [of these groups] need to recognize that continuous vision screening starting in early childhood is important. In addition to implementation, the data from those screening visits need to be collated for national database entry for improved monitoring in this country.What do you think should be the main takeaway from this report?In this country, if we elevate this condition to be considered a disease and recognize its impact on our children and ultimately on our future workforce, that would be monumental.
Myopia is projected to affect half of the world’s population by 2050. A new report says it needs to be countered by classifying it as a disease and upping children’s outdoor time
In 350 B.C.E. Aristotle noted that some people went about their days with what he called “short sight.” People with this condition, he found, would habitually narrow their eyelids to focus their vision—an observation widely credited as the first attempt at defining nearsightedness, or myopia. More than two millennia later, health officials are paying new attention to this old condition for a startling reason: myopia has reached epidemic levels worldwide.
Myopia’s prevalence has dramatically increased in recent decades, now affecting as much as 88 percent of the population in some Asian countries. Although it seems most acute in Asian cities, myopia’s growing prevalence is by no means an exclusively regional trend. By 2050, according to one estimate, five billion people—half the world’s population—will be nearsighted. The U.S., which has been less diligent than some other countries in tracking myopia cases, saw a jump in prevalence from 25 percent of people aged 12 to 54 in the early 1970s to 42 percent in the early 2000s, according to the last major national survey of the condition.
These statistics matter because myopia is a leading cause of visual impairment, and it can precipitate serious diagnoses that range from detached retinas to glaucoma.
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
A search is now underway for tangible measures to stem this rising tide. An expert panel from the National Academies of Sciences, Engineering and Medicine (NASEM) released a report in September entitled Myopia: Causes, Prevention, and Treatment of an Increasingly Common Disease. It lays out a series of recommendations, one of which calls for the Centers for Medicare & Medicaid Services to reclassify myopia as a disease that necessitates a medical diagnosis—a step that would encourage federal and state agencies, along with professional associations, to devote resources to reversing the situation. Notably, the committee also recommended that children spend one to two hours outdoors each day.
Terri L. Young, co-chair of the NASEM committee that produced the report and chair of the department of ophthalmology and visual sciences at the University of Wisconsin–Madison, talked with Scientific American about the implications of the myopia epidemic for people with myopia and policymakers.
[An edited transcript of the interview follows.]
I’d like to begin with the most basic of basics. Could you define what myopia, or nearsightedness, is?
I’ll start off with what a person with myopia experiences. Myopia is a condition in which an individual sees an object up close clearly but cannot see it clearly at a distance without optical correction. They have natural blurred vision at a distance.
Optically, there is a detailed definition that involves the very basics of how we see. Scattered light rays that enter the eye pass through multiple ocular components that reduce the scatter to focus the rays onto the retina, which converts the light into an electrical signal that is transferred through the optic nerve. The optic nerve is similar to a telephone cable that connects the eye to the occipital cortex at the very back of the brain, where what is viewed is then processed and interpreted.
The focus of those wavelengths that enter the eye and travel through all its optical components needs to coincide on the retina. In the case of nearsightedness, or myopia, the focus of the light occurs in front of the retina.
Myopia seems to be getting more attention lately, both in the U.S. and internationally. Why is that?
Myopia prevalence rates are at epidemic levels, especially in urban Asian communities, where in recent times upward of 80 to 90 percent of young individuals have developed myopia. There are large, government-sponsored myopia research institutes in many parts of Asia, including Taiwan, Singapore, China, Hong Kong and Japan.
Take Singapore, for example. All young men there are required to perform [two years] of military service after completing high school. Many of these military conscripts, and in particular the ones who are being prepared to go into battle or fly fighter planes, often need glasses or other corrective means for their myopia to fulfill those functions, causing concern for national security.
And what about in the U.S.?
It’s now certainly an issue in the U.S. as well. Research on myopia is conducted primarily in ophthalmologic and optometric training and research academic programs. But it hasn’t garnered, for whatever reasons, the same sense of urgency and funding as is the case for other parts of the world.
In the U.S., we don’t have good prevalence data for myopia and other refractive errors, such as astigmatism and hyperopia [farsightedness]. Health care in this country is so varied in terms of everything from access to dissemination of vision care; because we don’t have a nationalized health system, we also don’t have a national database to provide standardized tracking and reporting.
Aren’t there already simple ways to deal with myopia, such as getting a new prescription for glasses? Why is it perceived as becoming a global health problem?
Myopia correction is not just an inconvenience of glasses or contact lenses. It predisposes a person to other eye conditions that can lead to blindness. Higher degrees of myopia are associated with eye conditions: premature cataracts, glaucoma, retinal tears and detachments and myopic macular degeneration.
What’s happened in Asian communities is that the baseline level of refraction, the deflection of wavelengths as they pass through the eye, is trending toward nearsightedness. This shift is reflected in more individuals with high-grade myopia, with its increased ocular risks, as I described earlier. So instead of that group reflecting 3 to 5 percent of myopic individuals, it’s risen to 10 percent or more.
Access to quality vision care, with proper and standardized dissemination for all children, is a major issue in [the U.S.] There are many children who don’t have steady access to care and the opportunity for continued changes in spectacle correction as they grow. If they can’t see, they can’t learn. If they don’t learn, they may get discouraged. If they get discouraged, they tend to act out or to not perform well in school—which has lifelong educational, vocational and economic impacts.
Is there some idea why this myopia epidemic is happening?
Nowadays, children are indoors more often, and they’re not getting as much outdoor play. Outdoor light enables the visual system to process a variety of spectral wavelengths of light for a certain duration of time, and that affects normal eye development and growth. Our report reaffirms what has been in the scientific literature for more than 15 years: increased childhood outdoor time appears to be protective for myopia onset and development.
In urban Asia, education is highly regarded, and children undergo indoor schooling for relatively more hours per day—routinely with additional tutorial sessions on evenings and weekends. In Singapore, for example, there are fewer green spaces, and living situations are generally more vertical because of limited land mass. There are fewer nonclassroom hours and places for children to go outside to view the horizon for extended periods of time. That’s becoming more of the case in the urban U.S. as well.
What does being outside do to promote healthy eyes?
There are different and varied light wavelengths that enter the eye from outdoor versus indoor exposures. And there are differences in luminance—higher-intensity versus lower-intensity light levels. In the report, there is a lengthy discussion on what is called the “visual diet”—the environmental factors affecting the myopic eye—and there is a consensus that more research is needed.
What about the role of electronic devices in promoting myopia?
That’s certainly a trend that has exponentially grown in activity and use in our younger generations. I am a pediatric ophthalmologist. I see two- or three-year old children in my clinic who are comfortably playing with cell phones. This close-up activity is generally indoors. The limited research findings regarding electronic device impact on myopia development are inconclusive, however. Reflected in our report, studies could not support unequivocal evidence that using digital devices, especially electronic small devices, is an influencer for this shift toward myopia.
What measures have countries implemented to try preventing or correcting myopia in young people?
The Singapore Ministry of Health instituted outdoor playtime or recess during school hours. There are now programs in China and in Taiwan where classroom settings have been altered with the use of glass walls or colored light bulb use to increase outdoor daylight exposure. Children are undergoing treatment with atropine eye drops, which in some reports diminishes the shift toward myopia over time in the school-age years. The effect of the drops is not curative, however, and there are concerns regarding unknown long-term effects because we don’t quite understand the specific biochemical actions of atropine. Diagnosed children are also prescribed multifocal contact lenses or eyeglasses [progressive lenses that have different prescription zones to correct vision at different distances].
One of the main findings of the report that you co-chaired is the recommendation that myopia be classified as a disease. Can you explain why the consensus of the panel felt that was important?
The issue needs escalation to a recognized disease category to underscore its short- and long-term visual health consequences, and to attract attention and funding dollars on multiple and varied fronts for effective screening, treatment, prevention and research study.
It takes a multipronged team to elevate this issue. That groundswell would have to come from parents, educators and educator societies, local to national health care systems, local to national policymakers, public health experts, researchers, funding agencies, insurance companies, etcetera. All [of these groups] need to recognize that continuous vision screening starting in early childhood is important. In addition to implementation, the data from those screening visits need to be collated for national database entry for improved monitoring in this country.
What do you think should be the main takeaway from this report?
In this country, if we elevate this condition to be considered a disease and recognize its impact on our children and ultimately on our future workforce, that would be monumental.