A method of compensating for stains caused by deterioration of a display device, the display device including an illuminance sensor and a display panel including pixels and an optical fingerprint sensor, the method including determining, while in a test mode of the display device and via the illuminance sensor, whether an illuminance is a reference value or less, emitting, while in the test mode of the display device, first color light from the display panel when the illuminance is the reference value or less, and acquiring, while in the test mode of the display device, afterimage compensation data relating to amounts of deterioration of the pixels by receiving the first color light through an optical fingerprint sensor.