A display device includes a display panel, a plurality of readout circuits, and a deviation corrector. The display panel includes a plurality of pixels. The readout integrated circuits perform a readout operation of detected values including degradation information of the pixels, via readout lines connected to the pixels, when a degradation detecting operation is performed. The deviation corrector calculates weighted values to correct operating deviation of the readout integrated circuits based on an average of initial values. The deviation corrector generates corrected image data to correct input image data based on the weighted values. The initial values correspond to the detected values output from the readout integrated circuits when the display panel is in an initial state in which the pixels are non-degraded.