Gaze direction tracking system

A system for tracking a user's gaze direction (3.5), which comprises:

• a plurality of light sources (2.1) that emit infrared light onto at least one eye (1) of the user,
• a camera (2.2) configured to capture infrared images of the eye (1);
• a controller comprising at least one processor, wherein the controller is configured to:
• detect a plurality of flashes in an image of the eye (1), captured by the camera (2.2), each flash being a reflection of one of the light sources (2.1) on the visible surface of the eye (1);
• and
• to match each detected flash to the light source (2.1) that generated the flash on the visible surface of the eye (1);
• the plurality of light sources (2.1) is arranged in the form of a matrix covering, at least partly, the visible surface of the eye (1);
• and
• the controller is additionally configured to:
• analyse the image of the eye (1) and to determine to which region of the eye (1) each pixel of the image belongs;
• generate a 3D shape of the eye (1) from the plurality of flashes relative to an absolute geometric reference determined by the position of the camera (2.2) and the plurality of light sources (2.1);
• and
• define an ocular centre of rotation (3.1) of the eye (1) on the basis of the 3D shape of the eye (1), with which the gaze direction (3.5) is determined.