New research suggests the more time your child spends outdoor, the less likely he or she will develop myopia.

Myopia, which is commonly known as short-sightedness or nearsightedness affects 25 to 50 percent of adolescents in the West and that number increases to 80 percent of children in certain areas of south-east Asia. 

Researchers led by Dr. Cathy Williams, from the University of Bristol, and Dr. Jez Guggenheim, from the University of Cardiff, monitored short-sightedness in over 7,000 boys and girls in the Children of the 90s study at ages 7, 10, 11, 12 and 15 and evaluated the amount of time the children spent outside during the age of nine and the amount of physical activity they participated in at 11.

Children who spent more time outdoors during the ages of 8 and 9 were less likely to become short-sighted by the age of 15. Furthermore, newer information revealed 80 to 90 percent of children in Asia are short-sighted because they spend the majority of their time indoors.

"We’re still not sure why being outdoors is good for children’s eyes, but given the other health benefits that we know about we would encourage children to spend plenty of time outside, although of course parents will still need to follow advice regarding UV exposure," Dr. Williams said. "There is now a need to carry out further studies investigating how much time outside  is needed to protect against short-sightedness, what age the protective effect of spending time outside is most marked and how the protective effect actually works, so that we can try and reduce the number of children who become short-sighted." According to Dr. Peter Allen, College of Optometrists council member and Principal Lecturer and Director of Clinics at Anglia Ruskin University, this particular data is essential because it is the first to identify that by doing regular outdoor activities, you may be reducing your risk of becoming short-sighted.  

Researchers are unsure whether the reduction has anything to do with physical activity or merely being outdoors and future studies can help researchers understand the effects of being outdoors on eye health.

The study was published in Investigative Ophthalmology & Visual Science.