The world's increasingly urbanised cities and a reliance on technology are rapidly damaging our eyes, with a new study predicting one in two will be shortsighted by 2050 with one fifth at risk of blindness.
It's a bold claim but report co-author Kovin Naidoo told The Huffington Post Australia it was backed up by solid, peer-reviewed evidence.
"It is not a small thing to make a prediction like this -- when was the last time you heard a public health prediction that affects 50 percent of the world's population?" Naidoo told HuffPost Australia.
"This is a true global health crisis, and is rare in that whether you live in Africa or Australia, it will have a huge consequence."
The study published this week, pointed the finger at urbanisation, which lead people to spend less time outdoors, as well as "close-range activities" like reading phones, computer screens and books.
The research review, by the the Brien Holden Vision Institute at the University of NSW and the Singapore Eye Research Institute, also found the rate of people with myopia-related vision loss, which in some cases caused blindness, would increase seven-fold between 2000 and 2050.
It's estimated that there are currently 2 billion myopic people in the world, expected to increase to 2.6 billion in 2020 and 4.8 billion by 2050.
Naidoo, who is also chief executive officer of the Brien Holden Vision Institute said the research was compiled as one of Brien Holden's requests before he died.
"There was evidence coming in, early studies and small groups with alarming results that seemed to suggest dramatic implications but they were small studies. Brien brought us together and said 'this is a major public health crisis, the evidence is out there, we need to go after it'. We validated hundreds of studies to pull a meta analysis. The data was there."
Naidoo said that for a complex condition, there was an ironically simple way to prevent myopia.
"Various interventions have been researched but the one has got the greatest traction is that if children spend two hours or more a day outdoors, that is protective," Naidoo said.
"Some argue it’s about looking at further distances, and there's some evidence that it’s because of a chemical release in the retina. More results are coming in around the globe all the time but the reality is there is acceptance on the fact that spending two hours or more outside is protective.
"You could spend a long time reading computers and screens, but also spend two hours outdoors and it's still protective.
"From the time kids are small, they should be spending time outdoors and one good thing about Australia is we're culturally amenable to that concept."Suggest a correction