Abstract: A system formed by a device on the CCD or CMOS above a terminal display and a display screen setting program is disclosed. This system will set the working environment of a VDT user to an optimum value. The images of the VDT user and the peripheral environment are captured. Then the working environment of the VDT user, the illumination of the environment of the VDT user, the fatigue of the VDT user, and the distance between the VDT user and a display are determined. The brightness, contrast, colors and clearness of the font of the terminal display are adjusted and controlled automatically according to the illumination of the environment of the VDT user and the fatigue of the VDT user. When the illumination of the environment of the VDT user, the fatigue of the VDT user, and the distance between the VDT user and a display has been over a predetermined condition, an alarm will emit to inform the user.