A computer-implemented method for estimating head pose angles of a user includes determining a first rotation between a first head pose axis associated with a first image of a plurality of images of the user and a camera axis associated with a camera taking the images. A second rotation is determined between a second head pose axis associated with a second image of the user and the camera axis. The first and second head pose axes are determined based on light reflections within the plurality of images. A head pose angle of the user can be estimated based on the first rotation and the second rotation. An alert can be generated based on the estimated head pose angle.