1. A method of operating a user interface comprising a display for displaying a plurality of graphical objects, and a spatial detector for detecting a distance and/or a viewing angle of a user relative to the display, the method comprising: (a) using the spatial detector to detect a change of the distance and/or the viewing angle of the user relative to the display; (b) automatically adjusting at least one of position, orientation, size, shape, color, brightness, or contrast of at least one of the plurality of graphical objects displayed by the display, in dependence upon the change detected in step (a), so as to lessen a change of visible shape or size, and/or a change of visibility of the at least one graphical object to the user, resulting from the change detected in step (a); and (c) repeating steps (a) and (b) to continuously adjust the at least one of position, orientation, size, shape, color, brightness, or contrast of the at least one graphical object, so as to lessen changes of the visible shape or size, and/or changes of the visibility of the at least one graphical object, resulting from changes of the distance and/or the viewing angle of the user relative to the display.