Actuation mechanism for variable focal length spectacles

摘要

An actuating mechanism for spectacles which include two variable focal length lens units. Each lens unit is fitted with a coupling member which extends from the lens unit into the bridge of the spectacles. A linearly-movable finger-operated slider, having a finger pad extending above the bridge, causes a cam within the bridge to rotate as it is moved, the cam being coupled to the coupling members causing them to move and the focal length of the lens units thereby to change.