Operation of a head-worn display device in a motor vehicle includes a control device checking a condition of whether there is a vehicle occupant in the motor vehicle other than a driver, when the motor vehicle is not operated in an autonomous driving mode. If the condition is satisfied then a display of all content by the head-worn display device is stopped by the control device if the display device is virtual reality glasses and the display of exclusively traffic-relevant content by the display device is enabled by the control device if the display device is augmented reality glasses.