Answer: In the (double) blink of an eye.
Not only did someone just create contact lenses that can adjust their focus, but they also developed ones that can do so in the literal blink of an eye.
Scientists at the University of California, San Diego, created the prototype lens. The polymers in the lens respond to electrical currents, altering thickness and thus the focus of what is being viewed through the lens. It can quickly switch from focusing on what is close to the wearer versus what is far away from them and could even alter itself to function like a zoom lens on a camera.
But the science-fiction-like elements of the lenses don’t stop there. Thanks to an electrical field in the tissue surrounding the human eye, the lenses can be programmed to respond to the eye’s movements. The lens could focus on things that are close up when the wearer is looking in one direction, but then change that to be far away when they look somewhere else. And zooming in on something would require nothing more than blinking twice.