HEAD MOUNTABLE DEVICE WITH AN EYE-TRACKING SYSTEM AND METHOD FOR TRACKING A RESPECTIVE EYE OF A USER WEARING SUCH A HEAD MOUNTABLE DEVICE

The present invention relates to a head mountable device (100) comprising an eye-tracking system (200), comprising a first detecting subsystem (210) configured to detect at least one first gaze parameter of a 10 respective eye to be tracked when a user wears the head mountable device (100) so as to generate a first signal, wherein the first detecting subsystem (210) is of a low power monitoring type, and a second detecting subsystem (220) configured to detect at least one second gaze 15 parameter of the respective eye so as to generate a second signal, the second detecting subsystem (220) comprises a plurality of detecting elements (221, 222), a processing and control unit (230) associated to the first detecting subsystem (210) and to the second 20 detecting subsystem (220) configured to estimate a region of interest (400) among a predetermined plurality of regions of interest on the basis of said first signal, wherein the estimated region of interest (400) comprises the direction of the gaze of a respective eye to be 25 tracked, the processing and control unit (230) is configured to selectively activate one or more of the detecting elements (221, 222) on the basis of the estimated region of interest (400) for subsequently estimating the direction of the gaze of the respective 30 eye to be tracked inside the estimated region of interest (400) on the basis of said second signal with optimized hardware and computing energy consumption.