A display system including eye-tracking means, first image renderer, second image renderer, optical combiner and processor is described. Eye-tracking data is processed to determine gaze directions of user's eyes. Gaze location and gaze velocity and/or acceleration of user is determined based on gaze directions of user's eyes. It is detected whether or not gaze has been fixated for predefined time period based on gaze location and gaze velocity and/or acceleration of user. If gaze has been fixated, input image is processed to generate and render first image and second image substantially simultaneously. Projection of rendered first image and projection of rendered second image are combined optically by optical combiner to create extended-reality scene. If gaze has not been fixated, input image is processed to generate and render first image via first image renderer, whilst switching off or dimming second image renderer.