1. A macular region visual defect index calculation apparatus comprising: means for generating, on an output device, a visual field probe screen for probing a visual field of a subject using a static visual target; means for displaying and controlling a fixation image to be fixated by the subject during a visual field probe, on the visual field probe screen generated by said visual field probe screen generating means; means for setting a circular region surrounding the fixation image displayed by said fixation image displaying and controlling means, as a probe region in order to probe the subject's visual field using the static visual target; means for setting a plurality of probe points, with equal spacing, in the probe region set by said probe region setting means; means for displaying and controlling the static visual target sequentially on the probe points set by said probe points setting means to probe the visual field corresponding to the probe points; first counting means for counting, and storing on a memory device, a total number of said probe points at which the static visual target has been displayed by said visual target displaying and controlling means; second detection means for detecting that the static visual target, displayed by said visual target displaying and controlling means, has not been perceived; second counting means for counting via an arithmetic unit and storing on a memory device, the number of times of detecting, through said second detection means, that said static visual target has not been visually perceived; and means for calculating a visual defect index, via an arithmetic unit, by dividing said number of times counted and stored on the memory device by said second counting means, by said total number counted and stored on the memory device by said first counting means; wherein said probe region being set locally from a viewpoint of probing visual field characteristics mainly in macular region, and said visual defect index being a visual defect index from a viewpoint of probing visual field characteristics mainly in macular region.