A display device includes a processor and a display panel for receiving observation grayscale values from the processor. The display panel includes a data driver for applying data voltages to data lines, a target pixel coupled to at least one of the data lines, and observation pixels each coupled to at least one of the data lines, and located adjacent to the target pixel. The display panel applies a first data voltage to the target pixel, when the observation grayscale values for the observation pixels exceed a reference value. The display panel applies a second data voltage to the target pixel, when at least one of the observation grayscale values does not exceed the reference value. The first data voltage and the second data voltage are different from each other.