Hi @tzaccai, gaze data from any eye tracker is inherently noisy due mostly to the natural small movements of the eye even when fixating on a specific point. Indeed, it is for this reason that eye tracking applications depend on fixations rather than individual gaze points to determine the most likely locations a user is looking.
At a distance of around 30cm between the tracker and the user, one might anticipate a deviation of pixels up to around 10/12 pixels so your case is somewhat outwith nominal accuracy in the y dimension.
Can you kindly try the ‘gaze trace’ feature available within the Tobii Core Software Tray icon and let me know what kind of accuracy you experience when looking around the screen.. the size of the bubble indicates the approximate accuracy within which
the gaze is deemed to be looking. In addition, you can also try ensuring that the eye tracker is not close to any major sources of infrared light such as large open windows or spotlights in the periphery.