An apparatus comprising: a reference frame manager configured to insert reference frames (400A, 400B, 1004) comprising illumination points into media, the reference frames (400A, 400B, 1004) presented at a first frequency between media frames (1002, 1006) of the media; an image manager configured to identify images captured by a camera (140, 240), the images comprising reflections of the reference frames (400A, 400B, 1004) by at least one of an eye of a user and/or eyewear of the user; and a gaze analyzer configured to determine a portion of the media that is being viewed by the user (201, 1000) based on the images of the reflections, characterized in that the apparatus is further configured to: analyze conditions of an environment of the user, wherein the reference frame manager is configured to adjust settings of the illumination points within the reference frame based on the conditions of the environment, wherein the conditions of the environment comprise at least one of a location of the user (201, 1000), and a head location of the user (201, 1000) relative to the display, and wherein the settings of the illumination points comprise at least one of a location of the illumination points, a pattern of the illumination points, a size of the illumination points, a shape of the illumination points and a color of the illumination points. a reference frame manager configured to insert reference frames (400A, 400B, 1004) comprising illumination points into media, the reference frames (400A, 400B, 1004) presented at a first frequency between media frames (1002, 1006) of the media; an image manager configured to identify images captured by a camera (140, 240), the images comprising reflections of the reference frames (400A, 400B, 1004) by at least one of an eye of a user and/or eyewear of the user; and a gaze analyzer configured to determine a portion of the media that is being viewed by the user (201, 1000) based on the images of the reflections, characterized in that the apparatus is further configured to: analyze conditions of an environment of the user, wherein the reference frame manager is configured to adjust settings of the illumination points within the reference frame based on the conditions of the environment, wherein the conditions of the environment comprise at least one of a location of the user (201, 1000), and a head location of the user (201, 1000) relative to the display, and wherein the settings of the illumination points comprise at least one of a location of the illumination points, a pattern of the illumination points, a size of the illumination points, a shape of the illumination points and a color of the illumination points. analyze conditions of an environment of the user, wherein the reference frame manager is configured to adjust settings of the illumination points within the reference frame based on the conditions of the environment, wherein the conditions of the environment comprise at least one of a location of the user (201, 1000), and a head location of the user (201, 1000) relative to the display, and wherein the settings of the illumination points comprise at least one of a location of the illumination points, a pattern of the illumination points, a size of the illumination points, a shape of the illumination points and a color of the illumination points.