Over a billion people around the world need glasses but can’t get them. A new study with kids in China suggests that cheap glasses they can easily adjust themselves might be a solution.
Refractive error – or improperly corrected vision – is the biggest cause of low vision around the globe.
These ‘self-refracting’ glasses – called Adspecs and made by Adaptive Eyecare – can be adjusted to the right strength without trained optometrists, which are few in developing nations.
These oil-filled, self-adjustable glasses have been in the news for years and have already been given to 30,000 adults around the world by various aid organizations. But there's little evidence for their usefulness for children.
So the researchers gave these glasses to 554 urban school children ages 12 through 17 in Guangzhou, China. Then they compared the children’s ability to self-correct their vision – under teacher supervision – with the results of a professional eye exam.
The adjustable glasses work via special lenses made of a clear membrane filled with silicon oil and held between two plastic discs. As Reuters explains, the wearer can change the amount of oil in the lenses using a removable syringe and dial that attach to the glasses' frame. Adding or removing oil changes the curvature of the lenses, which alters their strength.
About 92% of the kids were able to correct their own nearsightedness using the glasses – compared with a nearly 100% rate when the students were given professional eye exams.
"What we have proven is the basic principle," says Oxford physicist Joshua Silver, founder of Adaptive Eyecare, coauthor on the study, and the director of the Centre for Vision in the Developing World. "The large majority of teenaged children in an area where poor vision from uncorrected refractive error is common can achieve vision sufficient to meet the demands of the classroom."
The specs cost only $19 per pair, but can’t correct astigmatism, are still too intricate to be robust, and aren’t really known for their stylishness. "A key part of further work will be the creation and test of designs which are appealing to kids and well-suited to the rough-and-tumble of daily life," Silver says.
His goal is to get the price down to $1 a pair and distribute 1 billion pairs worldwide by 2020.
Many developing nations have as few as one trained eyecare professional for every one million people. Refractive error will rise into the top 10 global health issues affecting productivity and opportunities by 2030 – even surpassing HIV/AIDS in its global burden.
Image: Adspecs via InventorSpot