VOA常速英语:UK Scientists Develop Cheap Adjustable Glasses

Ninety-five percent of people in Sub-Saharan Africa who need glasses don't own a pair, according to the Britain-based charity foundation Vision for a Nation.

Its founder, British philanthropist James Chen, says Rwanda — whose 11-million residents are served by 14 ophthalmologists — is just one nation where the need for the glasses is great, especially among schoolchildren.

“We expect that perhaps a million people in Rwanda will need some form of vision correction, and out of that probably 900,000 people will just need a simple reading glass, and we would be able to supply that," he says of his company, Adlens, which manufactures two types of adjustable glasses based on technology developed at Oxford University.

The glasses, he says, are easy to use and offer a wide range of magnification.

“You have two lenses, [and] as they move against each other, the part of the eye you can see out the power changes with the two lenses moving against each other," he says. "The other technology we have is the fluid-filled [lens], which is a chamber; on the one side you have a plastic kind of a sheet, and as you put in the fluid; which is a silicone oil, it changes the curvature of that and so that's what's changing the power.”

Adlens ophthalmologist Graham Mackenzie says the glasses are especially suitable for people with variable eyesight.

“If your eyesight does fluctuate from day to day, or even minute to minute, you can just readjust the lens power to meet your needs," MacKenzie says. "The technology as it currently stands has a very high power range — so high, in fact, that we can capture 90 percent of all the sorts of refractive errors that are out in the world.”

With a subsidy from the World Bank, Rwandans will pay only about $1.50 for the adjustable glasses, which is roughly equal to three-days' wages in the country.

The Vision for a Nation foundation has trained some 1200 nurses to help the vision-impaired learn how to use the product.

If everything goes well with the distribution and adoption of adjustable lenses in Rwanda, Vision for a Nation plans to distribute them in other countries, too.