Light output of a display can be dynamically adjusted on-the-fly. When implemented on a low-persistence display that supports a variable refresh rate, this dynamic light output adjustment maintains a constant brightness over a series of frames to eliminate flickering of the display. When pixel data of a given frame is output to a frame buffer for presenting an image on the display, a time difference between an illumination of the display's light emitting elements for a preceding frame and an upcoming illumination of the light emitting elements for the given frame may be determined, and this time difference is used to determine a value of a light output parameter. During presentation of the image on the display, the light emitting elements can be illuminated in accordance with the value of the light output parameter. This determination iterates over a series of frames to dynamically adjust the display's light output.