Half the world will need glasses by 2050?

If current trends continue, half the world’s population (almost 5 billion) will be short-sighted in just over three decades, with one-fifth of those expected to have an increased risk of blindness, a new study reports.

That’s a seven-fold increase in short-sightedness (or myopia) from 2000 to 2050, and despite the condition becoming so rapidly prevalent, scientists still can’t agree on what’s causing it. It would be easy to link our obsession with computer screens to the so-called myopia epidemic, but if only things were that simple.

Between the 1970s to the early 2000s, cases of myopia almost doubled in the US, and in certain parts of Asia, the rise has been even more dramatic, with a recent survey finding that as many as 96 per cent of teenagers in South Korea are short-sighted. In Singapore, China, and Japan the rate amount teens is around 80-90 per cent.

Now a new report by an international team of researchers has looked at the rise in myopia cases over the past few decades to come up with predictions for the future.

Looking at data from 145 studies covering 2.1 million participants, they found that in 2000, some 1,406 million people were diagnosed with myopia (22.9 per cent of the world population) and 163 million people had high myopia, which comes with an increased risk of blindness and cataracts.

“We predict by 2050 there will be 4,758 million people with myopia (49.8 per cent of the world population) and 938 million people with high myopia,” they conclude in the journal Ophthalmology.

So what’s going on here?
Just looking at how recently this has become a problem, it’s looking pretty likely that the sudden rise in myopia cases is linked to lifestyle and behaviour changes that have happened over the past few decades.

The researchers put it down to “environmental factors (nurture), principally lifestyle changes resulting from a combination of decreased time outdoors and increased near work activities, among other factors”.

We’re spending way more time indoors than any other period in human history, and very few of us could live without some serious daily screen time.

“Based on a handful of large epidemiological studies on myopia, spending time outdoors — especially in early childhood — reduces the onset of myopia,” Sarah Zhang reports for Wired.

Source: www.sciencealert.com