The Myopia Epidemic
Since the 1950’s, when researchers first started recording instances of myopia or shortsightedness, the condition has increased at a tremendous rate almost uniformly around the world.
It’s accelerating too: myopia among young people has doubled within a single generation, and it’s expected to, by some estimates, affect one-third of the world’s population — 2.5 billion people — by 2020.
To understand why this is, let me ask you a question:
Look in any direction as far as you can, and tell me, what do you see?
If you’re lucky, you may be able to turn your head and spot some trees or a hill in the distance. But the likelihood is, in most if not every direction, your gaze is suddenly thwarted by some sort of wall or man-made structure.
The thing is, unlike throughout most of human history, today we are domesticated creatures. We live in urban environments that serve our every need within a stone’s throw, and as a result, spend most of our times indoors — in vehicles, offices, lifts, supermarkets, shopping centres, and any other enclosed spaces we can climb into.
We no longer need to spend our days in the great outdoors, peering into the distance to admire the view or watch for predators; or make vast journeys during which we look out over the horizon to navigate our movements. With the development of the city, the combustion engine, and other modern technologies, all that is no longer necessary — not to mention impossible thanks to our non-stop work culture and constant haze of light and air pollution.
As you may by now have guessed, this closing in of boundaries above and around us is what researchers believe may have something to do with the significant rise in degrading distance vision.
Take for instance China, where, in the 1950s, between 10 and 20 per cent of people were shortsighted. Now — with its obsession with vertical cities and objective to become basically one big factory — just among teenagers and young adults alone, the percentage of those with shortsightedness is up at around 90 percent.
Seoul provides an even more extreme example. In the Korean capital, which is now home to some of the biggest companies in the world, 95 per cent of 19-year-old men are shortsighted — many of them severely and thus at high risk of losing their vision later in life.
It used to be thought that myopia was determined by our genes. But these undisputable correlations are proving that theory dead in the water. So now, rather than asking is it our physiology or the environment that determines our visual capabilities, researchers are moving toward a more important question:
Is it our modern indoor lifestyles with all its closed spaces, smartphones, and up-close tasks that’s to blame for the myopia epidemic? And if so, do we need to give it up to save our vision, or, as other research is suggesting, do we need to just make some radical but common sense changes?
An old answer to a modern problem
Several studies have shown that people who spend more time indoors are at greater risk of developing myopia.
But this is only one side of the story. Looked at it the other way, the studies also show the opposite: that those who spend more time outdoors are at less risk of developing myopia.
Although subtle, this switch in focus in looking at what makes being outdoors so much better for our eyes than being indoors, is what led researchers to study myopia in regards to the eye’s exposure to bright, natural light.
One of the first studies in this area involved little chicks wearing goggles. Researchers designed special eyewear to alter the resolution and contrast of incoming images for the chicks, so that they experienced the world through myopic eyes.
They then raised the chicks in a controlled environment under conditions in which only light intensity was changed. The results proved it was possible to induce the development of myopia by reducing exposure to light, showing that light levels akin to being outside slowed the development of shortsightedness in chicks by a huge 60 percent.
The science to back this up is pretty solid. Light stimulates the release of the neurotransmitter dopamine in the retina, which, in turn, blocks myopia’s characteristic elongation of the eye during its development. In short, light is key to growing and maintaining a pair of healthy, clear eyes.
Depending on if you are over or under the age of 30, the resulting advice for fighting the myopia epidemic may, then, be completely self-evident or utterly bewildering.
Go outside and get some sunshine and fresh air.