A fluorescence image acquisition method including: irradiating an eyeground with a short-pulse beam of light for exciting a fluorescent dye setting the time point of emission of the light as a reference, measuring the intensities of luminescence of the fluorescent dye at two different times which are predetermined periods of time after the reference, determining the ratio between the intensities of luminescence at the two different times, and detecting the intensity of luminescence of the fluorescent dye having marked a target by using the ratio and generating a fluorescence image of the fluorescent dye having marked the target, based on the results of detection by the detecting step.
