A lack of optometrists means many in the developing world ' n't get glasses . So far , 30,000 pairs of self-refraction glasses have been distributed around the world , through an adult literacy program in Ghana and the U.S. Military Humanitarian and Civic Assistance ( HCA ) Program . Josh Silver has developed glasses with lenses that can be removed by the wearer . The technology could be used to provide sunglasses for one billion people . Global Vision 2020 is training charity workers to wear the glasses .
A lack of optometrists means many in the developing world ' n't get glasses . Josh Silver has developed glasses with lenses that can be removed by the wearer . The technology could be used to provide sunglasses for one billion people . Global Vision 2020 is training charity workers to wear the glasses .