How can myopia be prevented in children?
Recent studies show that certain visual habits and environments result in less myopia and may help to prevent myopia.
A few tips for healthier eyes are:
- Spend more time outdoors: if children spend 80 to 100 minutes outdoors each day they are less likely to develop myopia.
- Take breaks when doing near work: the 20/20 rule says every 20 minutes take at least a 20 second break.
- Limit screen time: less than 3 hours screen time/day if possible. Also make sure that iPads and phones are held a suitable distance away when viewing.
Whilst the link between binocular vision and myopia is unclear, it’s important to optimize binocular vision in children. This involves ensuring the eyes work well together, see well together, track well together and align well together so the coordination between both eyes is as good as it can be.
Outdoor time & myopia prevention
Luckily, the best way to prevent myopia is also the cheapest and hopefully the easiest, and it’s to send children outside! Parents who are concerned about their children becoming myopic, should be mindful of the importance of outdoor time as a way of preventing myopia from starting.
Outdoor time has shown to be protective against the development of myopia in children & teenagers, regardless of how many hours are spent doing close work on screens. A review of the literature showed that spending time outdoors was found to have a protective effect for the onset of myopia. This means outdoor time helps reduce the risk that children will become myopic.
The magic numbers say spending 80 to 100 minutes outdoors each day is the key. There is not yet enough data to be certain that increased time outdoors helps to halt myopic progression for those children who were already shortsighted, but the studies have found that shortsighted children spend more time indoors than hyperopic (long-sighted) children.
Aside from the vision benefits, outdoor play is definitely a healthy habit to develop. There are numerous physical and psychological benefits to children getting outdoors and especially into nature.
The vision benefits aren’t simply related to just getting kids to take a break from reading and screens, nor is there a direct correlation to the actual physical activity done outdoors. It seems the secret is the brightness of outdoor light. Even on a cloudy day outdoors, and even with super bright artificial lighting indoors, outdoor light is many magnitudes brighter. This may be stimulating the young eye to grow at the correct rate, via a neurotransmitter in the eye and the brain called dopamine, and not at the accelerated rate as is the case in childhood myopia. It might also be about the process of looking far away, and having the whole of the retina (the light sensitive film at the back of the eye) stimulated in a more uniform way, compared to when we’re indoors and focussed on near reading and screens.
In China, where the prevalence of childhood myopia is at 80%-90%, there are schools experimenting with myopia prevention strategies including glass-walled ‘Bright Classrooms’ to simulate outdoor lighting conditions inside where the students spend most of their days.