A virtual-reality system includes a head-mounted display system comprising an eye tracker and a display screen comprising an array of pixels. The virtual-reality system monitors movement of a users eye using the eye tracker. A first plurality of frames for virtual-reality images is displayed on the display screen using a first persistence in accordance with a first display mode. The persistence is a percentage of a frame duration during which the array of pixels is activated. While displaying the first plurality of frames in accordance with the first display mode, a saccade of the users eye is detected. In response to detecting the saccade, the virtual-reality system switches from the first display mode to a second display mode having a second persistence that is greater than the first persistence. In the second display mode, a second plurality of frames for the virtual-reality images is displayed using the second persistence.