1. A method for controlling illumination within a vehicle, the method comprising: determining three-dimensional co-ordinates representing a point of origin in three-dimensional coordinate space based on a position of a vehicle occupant's head; determining a gaze direction of the vehicle occupant, wherein determining the gaze direction comprises using an eye tracking algorithm; using the determined point of origin and the determined gaze direction to plot a virtual projection, the virtual projection extending from the determined three-dimensional coordinates representing the point of origin in a direction of the determined gaze direction, wherein the virtual projection is three-dimensional, and is therefore capable of extending with an angular offset from each of three orthogonal axes intersecting the point of origin; and with reference to a three-dimensional model comprising a plurality of predefined areas of interest, determining that the virtual projection has intersected one of the plurality of predefined areas of interest and controlling an illumination source that is associated with the one of the plurality of predefined areas of interest to highlight a visual zone associated with the vehicle.