There is global evidence that exposure to outdoor light is key to reducing the myopia epidemic. According to Optometry Australia, children need to spend at least 90 minutes per day outside to help prevent myopia from developing and progressing. Sunlight helps dopamine release, which prevents axial growth of the eyeball.
In 2009, professor Ian Morgan at the Australian National University in Canberra set out to test whether boosting outdoor time would help to protect children’s eyesight. He launched a three-year trial in which a 40-minute outdoor class was added to the end of the school day for a group of children at six randomly selected schools in the Chinese city of Guangzhou. The test schools recorded a 23% lower incidence of myopia over three years.
Another study conducted in Taiwan and released in 2013 also found that children who were required to spend a total of 80 minutes, including recess time and lunch time, outdoors every day had their risk of nearsightedness reduced. At the beginning of the study, there were no significant differences between the schools in the interventional program and control schools with regard to age, gender and myopia prevalence (48% VS 49%). After one year, new onset of myopia was significantly lower in the intervention group than in the control group (8% VS 18%).
The latest research on Light Exposure and Eye Growth in Childhood measured children’s eye growth via wristwatch light sensors to record light exposure and found that less than an hour of bright light exposure per day appears to predispose children to faster eye growth and, hence, risk for myopia development. On the other hand, significantly slower eye growth was seen in the children who spent, on average, 120 minutes per day exposed to bright outdoor light levels.