A computer system for relieving an operator's fatigue includes an input device, an image processing circuit, a fatigue determination circuit, and an information generator circuit. The computer system also includes an output device, a response information storage device, and a fatigue degree criteria storage device. The operator's face is captured to create a model image of the face, which is analyzed to determine the fatigue degree of the operator. The response information corresponding to the fatigue degree is output to notify the operator.