Actuation mechanism for variable focus spectacles

Abstract From the Canadian patent

An actuating mechanism for spectacles which include two variable focus lens units. The mechanism mounts on the spectacle bridge; and includes two elongated drive levers mounted near opposite ends of the bridge each , extending toward the other end of the bridge. The free end of each driving lever is connected to its corresponding lens unit through a linkage. The driving levers are caused to rotate simultaneously but in opposite , directions, by a cam that is driven by a sliding member that slides along the bridge. By positioning the sliding member as desired the spectacles wearer , causes the cam to rotate thereby causing the driving levers to rotate and , both lens units to change …