This article is interesting, it claims that children who spend more time playing outside have better eyesight than those who spend more time indoors. The article claims that short sightedness has increased by 65% since the 1970’s in the US and puts this down to the fact that children are playing outside less.
Personally I think this is a load of rubbish. The condition is largely hereditary. All of my family suffer from short sight and have taken various measures to control it, from glasses and contact lenses, to myself who decided on laser eye surgery to address the problem. Regardless of whether we played outside or not ( and we did every day) we would still have the problem. Now a parent myself I fully expect my own children to need glasses unless they are very lucky and have their father’s good eyesight. In my opinion the increase of short sightedness is more down to the increased use of computers, smart phones and games machines and less down to whether a child plays outside or not.