1. A fundus image acquiring apparatus, comprising: a first fundus image acquiring unit for acquiring a first fundus image including at least one fundus image of an eye to be inspected; an extraction unit for extracting a characteristic image from the acquired first fundus image; a second fundus image acquiring unit for acquiring a second fundus image including at least two fundus images of the eye to be inspected, of which luminance is different from luminance of the acquired first fundus image, based on luminance information of the extracted characteristic image; and a detection unit for detecting a movement of the eye to be inspected based on the acquired second fundus image.