Mutually non-mixable light-transmitting insulative liquid and conductive liquid having different refractive indices are accommodated in a light-transmitting liquid container forming a lens unit. The lens unit includes a first electrode which is in contact with the conductive liquid, one or more second electrodes which are insulated from the conductive liquid, and a correcting section which controls voltage to be applied between the first electrode and at least one of the second electrodes in accordance with a gravity direction, thereby changing a shape of an interface between the insulative liquid and the conductive liquid to correct distortion of the interface caused by the gravity.