The days of wearing bifocals or constantly swapping out reading glasses might soon come to an end.
A team at University of Utah has created “smart glasses” with liquid-based lenses that can automatically adjust the focus on what a person is seeing, whether it is far away or close up. Research on the adaptive lenses was published this week in a special edition of the journal, Optics Express.
Most people who get reading glasses have to put them on and take them off all the time. Now they don’t have to do that anymore
The human eye has a lens inside that adjusts the focal depth depending on what you look at. But as people age, the lens loses its ability to change focus, which is why many people ultimately require reading glasses or bifocals to see objects up close and regular eyeglasses to see far away
The researchers have created eyeglass lenses made of glycerin, a thick colorless liquid enclosed by flexible rubber-like membranes in the front and back. The rear membrane in each lens is connected to a series of three mechanical actuators that push the membrane back and forth like a transparent piston, changing the curvature of the liquid lens and therefore the focal length between the lens and the eye.
The lenses are placed in special eyeglass frames with electronics and a battery to control and power the actuators
In the bridge of the glasses is a distance meter that measures the distance from the glasses to an object via pulses of infrared light. When the wearer looks at an object, the meter instantly measures the distance and tells the actuators how to curve the lenses.
If the user then sees another object that’s closer, the distance meter re-adjusts and tells the actuators to reshape the lens for farsightedness. The lenses can change focus from one object to another in 14 milliseconds. A rechargeable battery in the frames could last more than 24 hours per charge.
