It can be a hassle, taking your glasses on and off to switch between near and distant vision. There are bifocals, of course, plus there are now glasses on which you can adjust the focus. Scientists from the University of Utah, however, have gone one better – they've developed glasses that change focus automatically, depending on what you're looking at.
Each lens is made up of two clear rubber membranes – one in the front and one in the back – with a layer of clear viscous glycerin sandwiched between them. Three mechanical actuators push the rear membrane in and out, compressing or releasing the glycerin and thus changing the curvature of the lens. This, in turn, changes its focal length.
It's not unlike the technology utilized in the Adlens adjustable-focus glasses, although they're operated manually. By contrast, the Utah glasses incorporate an electronic distance meter in the bridge, which uses pulses of infrared light to determine how far away objects are from the eyes. Whenever that distance changes, it instructs the actuators to reshape the lenses accordingly. They do so in a claimed 14 milliseconds.
Source: newatlas.comAdded: 26 January 2017