Play outside and reduce short-sightedness?

For centuries, scientists like Kepler have speculated about the relationship between near work and the onset of myopia. There have been multiple studies to review the relevance of potential factors associated with the onset and/or progression of myopia.

Donald Mutti states that lack of time outdoors presents a more significant and robust risk than near work. Observing 4500 children over a twenty-year period, Zadnik et al. (2015) found no association between near work and risk of myopia, whereas increasing the time children spend outdoors was found to have an impact. While children with two myopic parents are typically reported to have a higher risk for developing myopia than children with just one (or no) myopic parent, the risk appears to decrease if these children spend more time outdoors.

According to studies carried out in Asia, although increasing time outdoors reduces the likelihood of myopia onset, it may or may not impact its rate of progression in a child who is already myopic. Mutti explained that the physiological process behind the onset and progression of myopia may be different.

The mechanism behind the "outdoors effect" is still unknown, and theories including the effects of improved image quality, ultraviolet radiation, increases in physical activity and higher exposure to Vitamin D have only shown small effects. Instead, Mutti suggested that the most promising hypothesis relates to higher levels of illumination, which may stimulate the production of dopamine, in turn inhibiting ocular growth.

Research worldwide continues to confirm the benefits of outdoor exposure, including the development of strategies for taking advantage of this finding, such as increasing the amount of time children spend outdoors and developing specialised classrooms with better access to natural light.