Binocular disparity limit in three-dimensional display systems

In three-dimensional display systems, binocular disparities must be limited within a certain fusional area, called as "Panum's fusional area". Otherwise, too larger disparity could cause double view or serious eye fatigue. However, the measurements about Panum's fusional area in the previous studies focused only on the horizontal arid vertical meridian of retina. For fully measuring the Panum's fusional area in more directions, we took the measurements of the limits of Panum's fusional area, in sixteen different directions from 0 degree to 360 degrees by a step of 22.5 degrees in the fovea. It was found that the horizontal disparity limit of binocular fusional area is about 32-38.4 min of arc and the vertical limit is about 19.2-24 min of arc. The disparity limits of binocular fusional area are approximately symmetrical about horizontal meridian. However, the disparity limits are not symmetrical about vertical meridian; the nasalward disparity limits are obviously larger than temporalward disparity limits. Moreover, in the nasal side of retina, the disparity limits decrease in a monotonic fashion, and in the temporal side, however, the disparity limits have no obvious difference.