In the UK, the average level of myopia is between 20% and 30%, and 20–30% was once the average among people in South East Asia as well, Australian National University Professor Ian Morgan explains — until recently:
“They’ve gone from something like 20% myopia in the population to well over 80%, heading for 90% in young adults, and as they get adult it will just spread through the population. It certainly poses a major health problem.”
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Professor Morgan argues that many children in South East Asia spend long hours studying at school and doing their homework. This in itself puts pressure on the eyes, but exposure to between two and three hours of daylight acts as a counterbalance and helps maintain healthy eyes.
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“We’re talking about the need for two to three hours a day of outdoor light — it doesn’t have to be massively sunny, we think the operating range is 10-20,000 lux, we’re not sure about that — but that’s perfectly achievable on a cloudy day in the UK.”