Through the present invention, a perimetry result is obtained for a position on a retina surface designated as a position to be tested. As illustrated in the drawing, “the position of a ganglion cell (RGC)” and “the position of a photoreceptor cell (C) for sending information to the ganglion cell (RGC)” are offset on the retina surface (macular part). Here, when position (P1) is designated as a test position for testing the functioning of a ganglion cell at position (P1), the perimeter of the present invention finds “the position (P2) of the photoreceptor cell for sending information to the ganglion cell at position (P1),” presents a visual target at position (P2) rather than position (P1), and tests a visual field. The information of the visual target is sent to the ganglion cell at position (P1), and the functioning of the ganglion cell can therefore be tested. The test result is correlated with the position (P1) and displayed, and the ganglion cell at the designated position (P1) can be therefore be tested.