(RxWiki News) A lot of kids look forward to recess during school. While spending more time in the great outdoors can allow kids to release that extra energy and give their brains a break, it might also help keep their vision strong and healthy.
Fewer children who spent recess outside became nearsighted than kids who were indoors more often at school, a recently published study found.
The onset of nearsightedness can be significantly impacted by outdoor activities during recess, according to the researchers.
"Give those eyes a rest; get outside and play."
Pei-Chang Wu, MD, PhD, of Kaohsiung Chang Gung Memorial Hospital in Kaohsiung, Taiwan, led researchers in investigating whether outdoor activity was linked to increases in nearsighted vision in elementary school kids.
Nearsightedness is a common term for when distant objects appear out of focus.
The study included 571 students between 7 and 11 years of age who were recruited from two schools in a suburban area of southern Taiwan.
Children from one school were encouraged to have recess outside. Those in the other school did not have any special programs during recess.
Parents of the children responded to surveys asking them about their children's eyesight, specifically the axial length of their eyes. The children also underwent eye evaluations at the beginning of the study and one year later.
At the start of the study, there were no significant differences in age, gender and prevalence of nearsightedness between the two schools.
Children who had recess outdoors spent about 11.2 hours each week outside, including 6.7 hours during recess, two hours for PE and another two and a half hours after school.
At the same time, children in the other group spent only 7.6 hours outside on average, with 3.3 hours during recess, two hours for PE and 2.3 hours after school.
After one year, the school that promoted outdoor recess had fewer new cases of nearsightedness compared to the school where students stayed inside more often, the researchers found.
Spending more time outside did not prevent children from becoming nearsighted. Children who had recess outside became less nearsighted than children who did not have recess outdoors.
The researchers said that having recess outdoors protected kids from becoming nearsighted, though they are still not sure how much time outdoors is required to prevent nearsightedness.
Being in the brighter light might also protect from increasing nearsightedness, according to the researchers. In addition, being in a higher school grade also protected children.
"More outdoor activities and breaks in near-range visual work may be beneficial in elementary schools to decrease [nearsighted] prevalence," the researchers wrote in their report.
Though the researchers are not sure how being outdoors is linked to nearsightedness, the results "hopefully will stimulate further study of factors which may prevent or limit the development of [nearsightedness]," according to Christopher Quinn, OD, FAAO, optometrist with Robert Wood Johnson University Hospital and dailyRx Contributing Expert.
"[Nearsightedness] is a significant public health problem and the authors are to be commended for looking at potential modifiable factors which can reduce the development of myopia," he said.
The authors noted that participants were not randomly assigned to have recess outside and came only from suburban areas. The hours each person spent outdoors was also not consistent.
Future studies should randomize children from more diverse residential areas and record the time children spent outside and the intensity of sunlight.
The study was published in the May issue of the journal Ophthalmology. No conflicts of interest were declared.
The Chang Gung Medical Research Project (CMRP) Research Grants from Kaohsiung Chang Gung Memorial Hospital funded the study.