Outdoor recess time can reduce the risk of nearsightedness in children

May 1, 2013, American Academy of Ophthalmology

Two new studies add to the growing evidence that spending time outdoors may help prevent or minimize nearsightedness in children. A study conducted in Taiwan, which is the first to use an educational policy as a public vision health intervention, finds that when children are required to spend recess time outdoors, their risk of nearsightedness is reduced. A separate study in Danish children is the first to show a direct correlation between seasonal fluctuations in daylight, eye growth and the rate of nearsightedness progression. The research was published in the May issue of Ophthalmology, the journal of the American Academy of Ophthalmology.

in childhood is correctable, but is also linked to development of severe forms of this in adulthood, which increases risks for potentially blinding diseases such as glaucoma and . Research on nearsightedness, also called myopia, is intensifying as the condition nears epidemic status in Asia and other regions, primarily in developed countries. In the United States nearsightedness has increased by more than 65 percent since 1970. Though myopia is often inherited, researchers are now assessing to help explain why myopia rates are rising so rapidly in some populations.

In one of the new studies, an elementary school in Taiwan required its 333 students to spend recess outdoors for a year from 2009-10 so that researchers could learn whether this would reduce myopia rates. A similar school nearby served as the and did not require outdoor recess. The children in the intervention school, many of whom had formerly spent recess indoors, now spent a total of 80 minutes per day outdoors.

Students at both schools received at the study outset and one year later. The results showed that significantly fewer children became nearsighted or shifted toward nearsightedness in the school that required outdoor recess, compared with the control school. The researchers recommend that elementary schools in Asia and other regions add frequent recess breaks and other outdoor activities to their daily schedules to help protect children's eye development and vision.

"Because children spend a lot of time in school, a school-based intervention is a direct and practical way to tackle the increasing prevalence of myopia," said the leader of the study, Pei-Chang Wu, M.D., PhD., of Kaohsiung Chang Gung Memorial Hospital in Kaohsiung, Taiwan.

A separate study on the impact of daylight exposure on eye development analyzed data collected in a 2005 clinical trial that included 235 Danish school children with myopia. The participants were divided into seven groups, each of which represented a different seasonal interval. Because daylight hours fluctuate markedly with the seasons in Denmark, from seven hours in winter to nearly 18 in summer, access to daylight was distinct for each group. Axial eye length – the distance from the front to the back of the eye – and vision were tested in each group of children at the beginning and end of their seasonal interval. Axial length is an important measurement because elongation of the eye indicates that the person's myopia is worsening. In the children with access to the fewest hours of daylight, eye growth averaged 0.19 mm; in those with access to the most daylight, eye growth was just 0.12 mm.

"Our results indicate that exposure to daylight helps protect children from myopia," said the leader of the study, Dongmei Cui, M.D., Ph.D., of Sun Yat-sen University, China. "This means that parents and others who manage children's time should encourage them to spend time outdoors daily. When that's impractical due to weather or other factors, use of daylight-spectrum indoor lights should be considered as a way to minimize ."

Explore further: More time outdoors may reduce kids' risk for nearsightedness

More information: [1] Increased Prevalence of Myopia in the United States between 1971-1972 and 1999-2004. Arch Ophthalmol 2009;127(12):1632-1639
[2] High heritability of myopia does not preclude rapid changes in prevalence. Clin Experiment Ophthalmol 2002;30:168 –72.

Related Stories

More time outdoors may reduce kids' risk for nearsightedness

October 24, 2011
A new analysis of recent eye health studies shows that more time spent outdoors is related to reduced rates of nearsightedness, also known as myopia, in children and adolescents. Myopia is much more common today in the United ...

Play outside -- it's good for your eyes

June 1, 2012
(Medical Xpress) -- New university research aims to shed light on why being outside can help children see better.

Time outdoors may reduce myopia in children

July 30, 2012
(HealthDay) -- Increasing time spent outdoors may reduce the development or progression of myopia in children and adolescents, according to a study published online July 20 in Ophthalmology.

Study identifies multiple genetic factors impacting development of nearsightedness

March 14, 2013
In the largest ever genome-wide association study on myopia, 23andMe, the leading personal genetics company, identified 20 new genetic associations for myopia, or nearsightedness. The company also replicated two known associations ...

Recommended for you

Study advances gene therapy for glaucoma

January 16, 2018
While testing genes to treat glaucoma by reducing pressure inside the eye, University of Wisconsin-Madison scientists stumbled onto a problem: They had trouble getting efficient gene delivery to the cells that act like drains ...

New study offers added hope for patients awaiting corneal transplants

January 9, 2018
New national research led by Jonathan Lass of Case Western Reserve University School of Medicine has found that corneal donor tissue can be safely stored for 11 days before transplantation surgery to correct eye problems ...

Diabetic blindness caused and reversed "trapped" immune cells in rodent retinas

January 3, 2018
Johns Hopkins researchers have discovered a cell signaling pathway in mice that triggers vision loss in patients with diabetic retinopathy and retinal vein occlusion – diseases characterized by the closure of blood vessels ...

Ophthalmologists increasingly dissatisfied with electronic health records

December 29, 2017
Ophthalmologists' use of electronic health records (EHR) systems for storing and accessing patients' medical histories more than doubled between 2006 and 2016, while their perceptions of financial and clinical productivity ...

Higher omega-3 fatty acid intake tied to lower glaucoma risk

December 26, 2017
(HealthDay)—Increased daily intake of ω-3 fatty acids is associated with lower odds of glaucoma, but higher levels of total polyunsaturated fatty acid (PUFA) intake are associated with higher odds of developing glaucoma, ...

Protein analysis allows for treatment of eye-disease symptoms with existing drugs

December 21, 2017
Demonstrating the potential of precision health, a team led by a researcher at the Stanford University School of Medicine has matched existing drugs to errant proteins expressed by patients with a rare eye disease.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.