See The World Clearer and Cheaper

Peoples with bad eyes in 3rd world and developing countries can rejoice and see better with easy dioptri adjustable glasses invented by Joshua Silver. Professor Joshua is a kind man who his glasses just for 20$.

With this innovative glasses, the lenses can be adjusted on the range of +6 to -6 Dipotres by using the removable syringes to fill the fluid into the lenses accordingly.

This is particularly useful for people in developing countries where specially trained optometrists are not available. In 1996 he formed a company, Adaptive Eyecare, to develop these adaptive ophthalmic lenses in partnership with the UK Government's Department for International Development, for distribution in developing countries.The company has developed prototype adaptive spectacles that can correct both far-sighted and near-sighted people, and these spectacles have been trialled in several countries in Africa and Asia. So far 30,000 of Silver's lenses have been distributed in 15 countries.

[Sources & Images]
# adaptive-eyecare.com
# en.wikipedia.org/wiki/Joshua_Silver