Measurement for the Panum's Fusional Area in Retinal Fovea Using a Three-Dimension Display Device

The limits of Panum's fusional area have been studied by many research groups. Those studies, however, focused only on the measuring direction of horizontal and vertical meridian. In this study, a new experimental method was employed by using a three-dimension display device to fully measure the limits of Panum's fusional area in eight different directions from 0 degree to 360 degrees with a step of 45 degrees in the retinal fovea. The following results were obtained: (1) the horizontal limit of Panum's fusional area in fovea is larger than the vertical limit; (2) the limits of Panum's fusional area are almost symmetrical about the horizontal meridian; (3) the limits of Panum's fusional area are not symmetrical about the vertical meridian; the nasalward limits are obviously larger than the temporalward limits; (4) the form of Panum's fusional area in retinal fovea is suggested to be an off-centered ellipse instead of a standard ellipse reported in previous works.