An information processing device detects iris images of cosmetic lenses. A candidate extraction means extracts different iris images corresponding to the same person to be a cosmetic lens candidate. A confidence level calculation means matches iris features of the cosmetic lens candidate with iris features of other cosmetic lenses, and calculates a confidence level indicating a cosmetic lens likelihood. A determination means determines that the cosmetic lens candidate is a cosmetic lens with respect to the calculated confidence level that is equal to or higher than a predetermined threshold value.