University of Utah engineering professors 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. A startup company, Sharpeyes LLC, will market the glasses. Before putting them on for the first time, users would input their eyeglasses prescription into an accompanying smartphone app, which then calibrates the lenses automatically via Bluetooth. After that, you may never need another pair.