An image display apparatus is disclosed. The image display apparatus includes a display panel, an illuminance sensor to sense an ambient illuminance of the display panel, a plurality of light sources disposed in an edge region of a back surface of the display panel to output light, a plurality of switching elements to switch the light sources, and a processor to control the switching elements, wherein, when a difference in local dimming data of an input image between adjacent first and second regions is above a first reference value, the processor controls driving times of at least some of the switching elements to decrease a difference in illuminance between the first region and the second region, based on the illuminance sensed by the illuminance sensor.