An illumination control system includes a signal detection unit for detecting a signal changed depending on an eye state of a person, an opening/closing determination unit for determining an opening/closing state of an eye of the person based on the detected signal, and a sight line detection unit for detecting a person's sight line direction with respect to an illumination device based on the detected signal. The illumination control system further includes a control unit for controlling the illumination device to reduce an illuminance when the opening/closing determination unit determines that the eye of the person is in a closed eye state, and to change an illuminance and a light color based on the sight line direction detected by the sight line detection unit when the opening/closing determination unit determines that the eye of the person is in an open eye state.