Hi @stephan-wyderhelbling-ch, thanks for your query. Unfortunately both HTC’s own SRanipal SDK and the Tobii XR SDK (which operates on top of HTC) do not offer individual eye metrics but rather provide a vector combining both eyes together.
The Struct containing the gaze ray for left and right eye combined is ‘TobiiXR_GazeRay’ which provides both the gaze origin and direction.
You can read about this in more detail @ https://vr.tobii.com/sdk/develop/unity/documentation/api-reference/
Perhaps this can be of use for your project? Please do check it out and let us know how you get on. Best Wishes.