These glasses can help everyone, not just the poor:
The wearer adjusts a dial on the syringe to add or reduce amount of fluid in the membrane, thus changing the power of the lens. When the wearer is happy with the strength of each lens the membrane is sealed by twisting a small screw, and the syringes removed. The principle is so simple, the team has discovered, that with very little guidance people are perfectly capable of creating glasses to their own prescription.
[Josh] Silver [a retired professor of physics] calls his flash of insight a “tremendous glimpse of the obvious” – namely that opticians weren’t necessary to provide glasses
Speaking of not needing opticians and making glasses more affordable, a year ago I discovered by accident something extremely useful: Wearing one contact lens is better than wearing two.
Wearing just one contact lens, I get good distance vision from the lensed eye and and good close-up vision from the unlensed eye. Wearing two contact lenses, I have poor close-up vision. Another benefit of one rather than two contact lenses is that one eye is contact-lens-free for a long time. And I go through contact lenses half as fast. I wear lenses that last one month so I switch monthly which eye has the lens.
No optician told me this. No optician has even figured this out, as far as I know.