ETP-223: Used to measure the peripheral field of vision. The apparatus comprises of a calibrated arc, revolving chart holder. The object carrier which moves over the arc, contains five colours and five apertures of different diameter, calibrated scale. At the back of the arc arrangement is provided for fixing of chart which has concentric circles corresponding to the degrees of arc. Adjustable chin rest. All fitted over a sturdy base with receptacle for keeping charts. For table top use. Completed with 100 charts.