An Australian study involving Chinese primary school students has linked children spending more time outdoors with a decreased likelihood of developing short- sightedness later in life.

The study, published in the Journal of the American Medical Journal (JAMA) earlier this week, tested the effect an extra 40 minutes of daily outside activity had on the vision of Grade 1 students in China.

Researchers monitored the children for three years and found a 23 percent reduction in myopia (short-sightedness) versus the control group, who spent the typical amount of time outside during school breaks.

The lead author of the study, Center for Eye Research Australia Professor, Mingguang He, explained why young students were sought for the study.

"This reduction is clinically important because we targeted young children around 6 years of age, and these children are at greater risk of progressing to severe myopia if they develop myopia early," Mingguang said in a media release on Friday.

"If we can delay the onset of myopia through a simple and cost- effective intervention like this, we can provide great long-term eye health benefits."

The Center for Eye Research Australia, an affiliate of the University of Melbourne, commissioned the research program.

In East and South East Asia, it has been estimated that 80 to 90 percent of high-school graduates suffer the condition with 20 percent of those classed in the "severe myopia" range.

There is a short-term fix for sufferers in the form glasses or contact lenses. However, in the long term they face the prospect of sight-threatening complications in the form of macular degeneration.

He said the connection between more time spent outdoors and improved vision was unclear.

However, Mingguang and his colleagues believe the eye retina could potentially be stimulated by bright, outdoor light.

He hoped the discovery would lead to parents and teachers dreaming up new ways for students to maximize their time spent outdoors.

"School-based initiatives could include even more time for classes outdoors, for example using school recesses to get children outdoors, encouraging parents to bring their children outdoors at weekend, or using new class-room design to provide higher indoor light intensities," he said.

"All of these strategies will help translate the research findings into community benefit."