PROBLEM TO BE SOLVED: To compute a correction value for accurately correcting an error of a visual axis caused by the individual difference of a subject.SOLUTION: This correction value computing device 101 acquires a visual axis vector V1 toward a screen 105 from an eyeball 121 based on the photographed image of the eye of the subject 120. The correction value computing device 101 computes a feature quantity that extracts features for every region on a display image SP based on the pixel value of pixels included in the display image SP on the screen 105 when photographing the photographed image of the eye of the subject 120. The correction value computing device 101 determines one of a plurality of regions as a gaze point W based on the feature quantity of every region, and computes a correction value unique to the subject 120 based on the visual axis vector V1 and a visual axis vector V2. The correction value for correcting the error of the visual axis caused by the individual difference of the subject can thereby be computed with high accuracy during visual axis direction.
