A medical Wide-Field-Of-View optical-tracking-system for determining the position and orientation of a target-object in a reference coordinate system. The system includes at least three light-emitters, at least one optical-detector and a processor. The processor is coupled with each optical-detector. One optical-detector is a Wide-Field-Of-View optical detector, which acquires an image of the light-emitters within the field-of-view thereof. Each Wide-Field-Of-View optical-detector includes an optical-sensor and two optical-receptors. The processor determines the position and orientation of the target-object in the reference coordinate system according to representations of the light-emitters. Each light-emitter is within the field-of-view of an optical-detector. Each optical-detector and each light-emitter is attached to one of the target-object and a reference-location. The target-object and the reference-location are respective elements in a tuple including two elements from a group consisting of a display, a patient-body-location, a-medical-tool, physician-body-location, and a fixed-position.