A method and a medical optical tracking system, wherein the medical optical tracking system is synchronized with at least one other medical optical tracking system, extraneous light signals of the at least one other optical tracking system are detected by way of a sensor or a camera used for tracking of the optical tracking system, temporal properties of the detected extraneous light signals are determined based on acquired sensor data or acquired camera images, and temporal properties of light signals generated by way of a light source of the optical tracking system and/or a measuring window of the sensor or the camera are defined, on the basis of the determined temporal properties of the extraneous light signals, such that the light signals from the light source and/or the measuring window lie in light signal pauses of the at least one other optical tracking system.