Joshua Silver, a British physicist, aims to make eyeglasses more readily available for poor people around the world. He has developed eyeglasses which can be adjusted by inflating or deflating a fluid filled lens. When the lens is properly adjusted, the adjusting syringe is removed and the glasses are ready to wear.
His glasses have been recently publicized in the Washington Post and on NPR. He states that the glasses cost $19 each now, but he hopes that when production is scaled up the cost will decrease to $1 each. 
The glasses are limited in that they do not correct for astigmatism and at this point correct from -6 to +6 diopters. Also, they would not come as bifocals, I imagine.
I wish Mr. Silver all the success. As someone who regularly works in third-world eye clinics, I know that this is something which could be a great benefit to the truly underserved.
I am sure Mr. Silver has investigated and been approached by all types of distribution possibilities. I hope that various for-profit models are seriously looked into, since businesses using very small margins and very high volumes have been used to gain widespread distribution of everything from shampoo to cell-phones in third-world countries. 
Also, the country of India has developed a model of private and charity eye care combined with low-cost lens manufacturing to bring cataract surgery to the poor.