The invention relates to a projection exposure apparatus (400, 100) comprising a projection objective (408, 107, 200), the projection objective (408, 107, 200) comprising an optical device (1), the optical device (1) comprising an optical element (2) having an optically effective surface (2a) and at least one electrostrictive actuator (3), which is deformable by a control voltage being applied, wherein the electrostrictive actuator (3) is functionally connected to the optical element (2) in order to influence the surface shape of the optically effective surface (2a). A control device (4) is provided in order to supply the electrostrictive actuator (3) with the control voltage, wherein a measuring device (5) is provided, which is configured, at least at times while the electrostrictive actuator (3) influences the optically effective surface (2a) of the optical element (2), to measure directly and/or to determine indirectly the temperature and/or a temperature change of the electrostrictive actuator (3) and/or the surroundings thereof in order to take account of a temperature-dependent influence during driving of the electrostrictive actuator (3) by the control device (4).