Various embodiments of an endoscope capable of varying a focal length electrically are disclosed. In one embodiment, the endoscope comprises an optical imaging system within an inner portion of the elongate tube, wherein the optical imaging system comprises a liquid crystal adaptive lens (LCAL) comprising a ground plate, a first reference plate, a first liquid crystal layer and a first plurality of closed-loop electrodes configured to receive variable control voltages and a control system configured to adjust variable control voltages. In another embodiment, the LCAL in the endoscope may further comprise a second reference plate, a second liquid crystal layer and a second plurality of closed-loop electrodes.
