|In sub-Saharan Africa, finding an optometrist is like finding the proverbial needle in a haystack. There is only one per every one million people. So when British inventor Josh Silver came up with a design for glasses that don't need to be prescribed by an eye doctor, he knew he might be on to something incredibly useful.|
The spectacles use a set of fluid-filled plastic lenses. The water pressure in the sealed lens cell is controlled by a pump adjusted by the wearer. When the user reaches the correct level of magnification, he or she fixes the adjustment, resulting in corrected vision -- without a prescription.
Professor Silver heads up the Centre for Vision in the Developing World at Oxford University.