British Inventor Josh Silver has developer a pair of eyeglasses that are instantly adjustable. They've got a liquid-filled sac in the middle—add more fluid to make the glasses stronger, deflate to weaken them.
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.
