Method for operating a visualization system in a surgical application, and visualization system for a surgical application

A visualization system for a surgical application, comprising:

• a registration device,
• a communications link,
• a head-mounted visualization device with a display device,
• a sensor system which is configured to register a viewing direction of a user, and
• a control device,
• wherein the registration device is configured to provide a video data stream with a first image size as an output,
• wherein the control device is configured to generate an image excerpt of the video data stream, the image excerpt being a cropped portion of the video data stream, with a second image size smaller than the first image size, that is defined within the video data stream based on, and tracks any changes in, the registered viewing direction of the user, and to transmit said image excerpt via the communications link to the visualization device, and
• wherein the visualization device is configured to display the transmitted image excerpt on the display device.