A sensor arrangement comprises an input surface, an optical sensor, a first capacitive sensor, an evaluation unit and a device. The input surface has at least one light-permeable part surface. The optical sensor is disposed below the at least one light-permeable part surface. The first capacitive sensor is disposed below the input surface. The evaluation unit is coupled to the optical sensor and configured to carry out a light-permeability measurement of an object located on the input surface using the optical sensor. The device is configured to evaluate a change in capacitance of the first capacitive sensor. The device is connected to the first capacitive sensor and further configured to generate a first output signal if there is a change in capacitance. The evaluation unit is further configured to generate a presence signal if a measured light permeability falls below a predetermined value.