WORLDVIEW | INNOVATORS
From a Visionary English Physicist, Self-Adjusting Lenses for the Poor
Saturday, January 10, 2009
Joshua Silver remembers the first day he helped a man see.
Henry Adjei-Mensah, a tailor in Ghana, could no longer see well enough to thread the needle of his sewing machine. He was too poor to afford glasses or an optometrist. Then Silver, an atomic physicist who also taught optics at Oxford University, handed him a pair of self-adjusting glasses he had designed, and suddenly the tailor's world came into crystal-clear focus.
"He grinned and started operating his machine very fast," said Silver, 62, who aims to distribute his special glasses throughout the developing world.
Silver said he wants to provide eyeglasses to more than a billion people with poor eyesight. For starters, he hopes to distribute a million pairs in India over the next year or so.
In the United States, Britain and other wealthy nations, 60 to 70 percent of people wear corrective glasses, Silver said. But in many developing countries, only about 5 percent have glasses because so many people, especially those in rural areas, have little or no access to eye-care professionals.
Even if they could visit an eye doctor, the cost of glasses can be more than a month's wages. This means that many schoolchildren cannot see the blackboard, bus drivers can't see clearly and others can no longer fish, teach or do other jobs because of failing vision.
"It's about education, economics and quality of life," Silver said.
The glasses, which are made in China, are not sleek. In fact, he acknowledged, "detractors call them ugly." He said the design can be improved, but the current model looks like something from the back of Woody Allen's closet -- thick dark frames with round lenses. The glasses work on the principle that the more liquid pumped into a thin sac in the plastic lenses, the stronger the correction.
Silver has attached plastic syringes filled with silicone oil on each bow of the glasses; the wearer adds or subtracts the clear liquid with a little dial on the pump until the focus is right. After that adjustment, the syringes are removed and the "adaptive glasses" are ready to go.
Currently, Silver said, a pair costs about $19, but his hope is to cut that to a few dollars.