Children have always been encouraged to play outdoors for good general health, but could this activity actually protect them from becoming short-sighted?
The answer is yes, according to recent studies in East Asia. Latest research results presented at the recent International Myopia Conference in Birmingham, UK, showed some very interesting results: not only did outdoor play reduce the risk of developing myopia in kids who were NOT short-sighted, it also slowed down the myopia from getting worse in kids who ALREADY wore glasses for short-sightedness.
Recess outside classroom – the way forward
One of the studies involved an intervention program in Taiwanese schools over a 12-month period (ref 1) called 'Recess outside classroom'.
700 kids in Year 1 (6-7 years old) took part in the study. Half of the children stayed indoors during recess and the other half had to spend recess outdoors. In total, these children spent 80 minutes more outdoors per day compared to the ‘indoor’ group. Sounds like a good idea on a number of levels, but the results in terms of myopia were nothing short of amazing.
As a child’s myopia progresses, their eye continues to grow in length, making their myopia worse over time. For kids who were already short-sighted (myopic) the ‘outdoor play’ group had a 30% reduction in the amount of growth of the eye (compared to the indoor group). This is one of the easiest forms of myopia control.
The same study also backs up previous studies showing that the risk of non-myopic kids developing myopia is lowered by more time spent outdoors. Kids with more outdoor play had a significantly lower risk of becoming short-sighted compared to kids with less time outdoors.
In the Taiwanese study, only 8% of the outdoor play children developed myopia, compared to 18% of the ‘indoor’ group. Kids with normal vision have a significantly lower risk of developing myopia if they spend more time outdoors.
This is great news for kids at risk of developing myopia when they’re older (due to family history, East Asian race, etc). Get them outdoors!
Australian schools lead the way…
When it comes to outdoor play, Aussies do it better than their East Asian counterparts – at least when they are at school.
Australian children aged 10-12 years of age were found to spend an average of 105 minutes per day outdoors, compared to the average of 61 minutes spent outdoors by Singaporean children. And the major difference was during school hours.
We’re doing it better, it would seem. This additional exposure to light not only reduces the risk of developing myopia in the first place, it also slows down the worsening of myopia in kids who are already short-sighted.
Is a brightly-lit classroom just as good?
No. One of the other really interesting studies involved strapping a light meter to the heads of mannequins and measuring their exposure to light in various places – inside classrooms, next to windows, outdoors in full sun, shade and even with a hat on. Outdoors in shade with a hat on mimics well what happens with Australian children during recess.
Brightness of light is measured in lux. Outdoor unsheltered brightness is about 18,000 lux, compared to only about 400 lux indoors – even next to a large window.
What about sunglasses?
Aussie kids have been raised on slip-slop-slap, so how does that fit with the ‘outdoor play’ studies? Interestingly, what the researchers found was that even in a hat and wrap-around sunglasses and sitting in the shade, brightness reaching the eye is still 1,000 to 2,000 lux – four times higher than sitting indoors next to a window. So there's no reason to ditch the hats and sunglasses!
In conclusion, time outdoors (even in a hat in the shade) really does work to prevent or curtail myopia. This applies to kids at risk of becoming short-sighted as well as those who are already short-sighted.
Worried about your child's myopia? Call The Eye Practice on (02) 9290 1899 or make an appointment online today.
1. Wu PC, Tsai CL, Wu HL, Yang YH, Kuo HK. Outdoor activity during class recess reduces myopia onset and progression in school children. Ophthalmology. 2013;120(5):1080-5.