A measuring system having a measuring tool which includes a probe body and an optical marker, a camera for recording image data of the measuring tool, and an evaluation and control unit which is configured to evaluate the image data recorded by the camera and use the data to determine spatial position coordinates of the optical marker. The evaluation and control unit is also configured to calculate the deformation of the measuring tool due to external mechanical loading acting on the measuring tool, and to determine spatial position coordinates of the probe body based on the spatial position coordinates of the optical marker and the calculated deformation.