The no-optician-required glasses rely on the principle that the fatter a lens is, the more powerful it comes, so by pumping in or sucking out fluid, the glasses can be instantly tailored to the right strength. They're so simple to adjust that practically anyone can do it. So far the only complaint with the glasses is that they're kind of ginormous—which kind of goes with having specs that operate on the coke-bottle glasses principle and have a fluid-filled membrane sitting in the middle of the lens.

Silver is planning a trial in India that will distribute over 1 million of the glasses, which he hopes to have strapped to the heads over a billion of the world's poorest people—at a cost of $1 per pair—by the poetic date of 2020. Luckily for him, giant glasses are ironically cool again, so he could probably launch a Get 1, Give 10 style program funded entirely by hipsters . [Guardian via MAKE]

The technology is simple: There is a computer in the cinema that emits the subtitles to within 50 meters, and also deals with their synchronization. A receptor in the glasses captures the signal and projects it onto the microscreen, which fits over the right-hand lens. It's easy as pie to use—one button turns the gadget on and off and another one restarts it. – Ad Dugdale

Gafas con subtitulos a la carta [El Mundo]