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.
Opticians used to deliberately give children “weak” prescriptions, to encourage the eye to self-correct. Until the research showed that any blurry image on the retina spurred growth (worsening the outcome continuously). So, not a great idea for everyone.
I’ve worn the same contact lenses for three years. The previous pair lasted ten years. (Hard lenses; the “gas permeable” technology has been perfected.) It’s obvious why lens manufacturers promote disposable lenses, but it should be just as obvious why we’re better off resisting them, even if you neglect (appalling) infection rates.
My last optician, at a mall chain store, did suggest using two different strengths of lens, as an alternative to lenses and also reading glasses. She also offered two weak lenses, tuned for reading, along with driving glasses. What I’m using is two strong lenses along with reading glasses. I find myself wearing the glasses most of the day. The advantage of reading glasses is that they’re cheap. I go through two pair a year. Of course they’re all made in China.
My optometrist knows about using only one contact lens, or different prescriptions for each, instead of using reading glasses.