Children who spend time outside are far less likely to develop myopia - more commonly known as short-sightedness - researchers from Bristol University have said.
They found that if children spent a long time outside, they had good vision, regardless of family history, how much time they spent reading or if they took part in much physical exercise.
The scientists came to the results after looking at eye tests from 7,000 children in South West England, who had examinations aged seven, 10, 11, 12 and 15, and considering the amount of physical activity they had during the week.
They found that those children who spent regular time outdoors aged 8-9 were half as likely to be short-sighted by the time they were 15.
Dr Cathy Williams, who led the research, said: "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.
"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."
Story posted by Robert Mair on 3/8/2012