A lens curvature variation apparatus for varying a curvature of a liquid lens based on an applied electrical signal, the lens curvature variation apparatus comprising: a lens driver to apply the electrical signal to the liquid lens; a sensor unit to sense the curvature of the liquid lens formed based on the electrical signal; and a controller to control the lens driver to form a target curvature of the liquid lens based on the sensed curvature, wherein the sensor unit senses a size of an area of a boundary region between an insulator on an electrode and an electroconductive aqueous solution in the liquid lens or a change in the size, wherein the liquid lens comprises: a common electrode; a plurality of electrodes (540a-540d) spaced apart from the common electrode; and a liquid and the electroconductive aqueous solution disposed between the common electrode and the plurality of electrodes, characterised in that the controller is configured such that the curvature of the liquid lens increases as a time difference between a first pulse applied to the common electrode and a second pulse applied to any one of the plurality of electrodes increases, wherein the first pulse includes: a first section having a first high level, a second section having a second high level lower than the first high level and a third section having a low level, wherein the second section of the first pulse signal is applied to the common electrode during a turn-on period of a switching element connected to at least one of the common electrode and the plurality of electrodes, wherein the sensor unit senses a capacitance of a boundary region between an insulator on any one of the common electrode and the plurality of electrodes and an electroconductive aqueous solution in the liquid lens during the second section in the turn-on period of the switching element. a lens driver to apply the electrical signal to the liquid lens; a sensor unit to sense the curvature of the liquid lens formed based on the electrical signal; and a controller to control the lens driver to form a target curvature of the liquid lens based on the sensed curvature, wherein the sensor unit senses a size of an area of a boundary region between an insulator on an electrode and an electroconductive aqueous solution in the liquid lens or a change in the size, wherein the liquid lens comprises: a common electrode; a plurality of electrodes (540a-540d) spaced apart from the common electrode; and a liquid and the electroconductive aqueous solution disposed between the common electrode and the plurality of electrodes, characterised in that the controller is configured such that the curvature of the liquid lens increases as a time difference between a first pulse applied to the common electrode and a second pulse applied to any one of the plurality of electrodes increases, wherein the first pulse includes: a first section having a first high level, a second section having a second high level lower than the first high level and a third section having a low level, wherein the second section of the first pulse signal is applied to the common electrode during a turn-on period of a switching element connected to at least one of the common electrode and the plurality of electrodes, wherein the sensor unit senses a capacitance of a boundary region between an insulator on any one of the common electrode and the plurality of electrodes and an electroconductive aqueous solution in the liquid lens during the second section in the turn-on period of the switching element. a common electrode; a plurality of electrodes (540a-540d) spaced apart from the common electrode; and a liquid and the electroconductive aqueous solution disposed between the common electrode and the plurality of electrodes, characterised in that the controller is configured such that the curvature of the liquid lens increases as a time difference between a first pulse applied to the common electrode and a second pulse applied to any one of the plurality of electrodes increases, wherein the first pulse includes: a first section having a first high level, a second section having a second high level lower than the first high level and a third section having a low level, wherein the second section of the first pulse signal is applied to the common electrode during a turn-on period of a switching element connected to at least one of the common electrode and the plurality of electrodes, wherein the sensor unit senses a capacitance of a boundary region between an insulator on any one of the common electrode and the plurality of electrodes and an electroconductive aqueous solution in the liquid lens during the second section in the turn-on period of the switching element. a first section having a first high level, a second section having a second high level lower than the first high level and a third section having a low level, wherein the second section of the first pulse signal is applied to the common electrode during a turn-on period of a switching element connected to at least one of the common electrode and the plurality of electrodes, wherein the sensor unit senses a capacitance of a boundary region between an insulator on any one of the common electrode and the plurality of electrodes and an electroconductive aqueous solution in the liquid lens during the second section in the turn-on period of the switching element.