PROBLEM TO BE SOLVED: To provide a crystalline lens image analysis instrument which permits an NUC classification to be objectively and automatically assessed in a cataract diagnosis.SOLUTION: The crystalline lens image analysis instrument includes an image acquisition means 200 for acquiring optical cut plane image data of an eye to be tested which is obtained by photographing the eye, a specific area setting means 202 for setting a specific area 41 including at least partially an embryonic nuclear area or to be set in the vicinity of the embryonic nuclear area from the acquired optical cut plane image data in the interior of the crystalline lens area 40, a center-to-center layer detection means 203 for detecting whether the center-to-center layer exists or not in the set specific area 41, and a grade decision means 204 for deciding that a nuclear cataract belongs to a first grade group for which an NUC classification grade for assessing the nuclear cataract is low when the center-to-center layer exists and deciding that the nuclear cataract belongs to a second grade group for which the NUC classification grade is high when the center-to-center layer does not exist.
