New smart glasses automatically focus on what a person sees

A team at the University of Utah, led by electrical and computer engineering professor Carlos Mastrangelo and doctoral student Nazmul Hasan, created a pair of smart glasses equipped with liquid-based lenses. The glasses can automatically adjust the focus on what a person sees, whether that be far away or close up.

Those who have reading glasses are often required to put them on and take them off frequently but won’t have to any longer with these new smart glasses.

“You put these on, and it's always clear,” said Mastrangelo.

The human eye has a natural lens inside that adjusts the focal depth of what you’re looking it, but as we get older, that lens loses its ability to change focus. This is why several people need reading glasses or bifocals to see objects up close and conventional eyeglasses to see far away.

Knowing this, the team developed eyeglass lenses made of glycerin, a thick colorless liquid confined by flexible membranes in both the front and back. In each lens, the membrane in the back is connected to three mechanical actuators that push it back and forth and change the curvature of the liquid lens. As a result, this changes the focal length between the lens and the eye.

“The focal length of the glasses depends on the shape of the lens, so to change the optical power, we actually have to change the membrane shape,” Mastrangelo said.

Additionally, the team created unique eyeglass frames to place the lenses inside of, equipped with electronics and a battery to control and power the actuators. Located in the bridge of the smart glasses is a distance meter used to measure the distance from the glasses to an object via infrared light pulses.

When the user looks at an object, the meter instantly detects the distance and relays to the actuators how to curve the lenses. If the wearer sees an object that’s closer, the distance meter readjusts, telling the actuators to reshape the lenses to account for farsightedness. The lenses can change focus from one object to another within 14 milliseconds, and the rechargeable battery frames last for more than 24 hours per charge.

Before users can wear the glasses for the first time, they will need to input their eyeglasses prescription into a consequent smartphone app that automatically calibrates the lenses via Bluetooth. A wearer is only required to do this once, except if his or her prescription changes over time. Ideally, eyeglass wearers will never have to purchase another pair of these glasses again because the device adjusts to anyone’s eyesight.

Presently, the team created a bulky working prototype that they put on display at last month’s Consumer Electronics (CES) show in Las Vegas. However, they are working to improve the design to make them smaller and lighter. The smart glasses are expected to be available at retail in three years through a startup called Sharpeyes LLC.

Source: Phys.org