A cognitive impairment diagnostic apparatus, comprising: a display which displays a video for diagnosis of cognitive impairment on a display surface; an imaging unit configured to capture images of an eye of a subject; a detection unit configured to detect viewpoints of the subject on the display surface in time series based on the images captured by the imaging unit; a creation unit configured to create a distribution map representing a distribution of the viewpoints detected by the detection unit; a storage unit configured to store case characteristic data indicating a characteristic of a viewpoint distribution corresponding to a typical case in cognitive impairment; and a diagnostic unit configured to diagnose cognitive impairment of the subject by determining whether the distribution map has the characteristic indicated by the case characteristic data, characterized in that: the video for diagnosis is a video including: a first image which includes a correct-answer graphic symbol and does not include any graphic symbol other than the correct-answer graphic symbol; and a second image which includes the correct-answer graphic symbol and a plurality of graphic symbols similar to the correct-answer graphic symbol, the display displays the first image to cause the subject to memorize the correct-answer graphic symbol, and displays the second image to evaluate memory recall of the subject immediately after the display of the first image is ended, the case characteristic data indicates a characteristic that cognitive function is lower as a percentage of viewpoints of the subject present in a display area of the correct-answer graphic symbol in the second image is smaller, and the diagnostic unit is configured to calculate the percentage of the viewpoints present in the display area of the correct-answer graphic symbol in the distribution map, and diagnose that there is a possibility of a decrease in cognitive function when the calculated percentage is smaller than or equal to a threshold value. a display which displays a video for diagnosis of cognitive impairment on a display surface; an imaging unit configured to capture images of an eye of a subject; a detection unit configured to detect viewpoints of the subject on the display surface in time series based on the images captured by the imaging unit; a creation unit configured to create a distribution map representing a distribution of the viewpoints detected by the detection unit; a storage unit configured to store case characteristic data indicating a characteristic of a viewpoint distribution corresponding to a typical case in cognitive impairment; and a diagnostic unit configured to diagnose cognitive impairment of the subject by determining whether the distribution map has the characteristic indicated by the case characteristic data, characterized in that: the video for diagnosis is a video including: a first image which includes a correct-answer graphic symbol and does not include any graphic symbol other than the correct-answer graphic symbol; and a second image which includes the correct-answer graphic symbol and a plurality of graphic symbols similar to the correct-answer graphic symbol, the display displays the first image to cause the subject to memorize the correct-answer graphic symbol, and displays the second image to evaluate memory recall of the subject immediately after the display of the first image is ended, the case characteristic data indicates a characteristic that cognitive function is lower as a percentage of viewpoints of the subject present in a display area of the correct-answer graphic symbol in the second image is smaller, and the diagnostic unit is configured to calculate the percentage of the viewpoints present in the display area of the correct-answer graphic symbol in the distribution map, and diagnose that there is a possibility of a decrease in cognitive function when the calculated percentage is smaller than or equal to a threshold value. the video for diagnosis is a video including: a first image which includes a correct-answer graphic symbol and does not include any graphic symbol other than the correct-answer graphic symbol; and a second image which includes the correct-answer graphic symbol and a plurality of graphic symbols similar to the correct-answer graphic symbol, the display displays the first image to cause the subject to memorize the correct-answer graphic symbol, and displays the second image to evaluate memory recall of the subject immediately after the display of the first image is ended, the case characteristic data indicates a characteristic that cognitive function is lower as a percentage of viewpoints of the subject present in a display area of the correct-answer graphic symbol in the second image is smaller, and the diagnostic unit is configured to calculate the percentage of the viewpoints present in the display area of the correct-answer graphic symbol in the distribution map, and diagnose that there is a possibility of a decrease in cognitive function when the calculated percentage is smaller than or equal to a threshold value.