1. A fundus oculi observation device that has a forming part configured to form a motion image of a fundus oculi, an interference-light generator configured to split a low-coherence light into a signal light and a reference light and superimpose the signal light propagated through the fundus oculi and the reference light propagated through a reference object to generate an interference light, and a detector configured to detect the interference light, and that forms a tomographic image of the fundus oculi based on a result of detection of the interference light, the fundus oculi observation device comprising: a scanner configured to scan the fundus oculi with the signal light; a storage configured to store a still image of the fundus oculi; a specifying part configured to, when a motion image is being formed by the forming part, specify an image region in the motion image corresponding to a region of interest in the still image; a scan setting part configured to set a scan region including the image region in the motion image; and a controller configured to control the scanner to scan with the signal light within the scan region based on the image region, and the fundus oculi observation device forming a tomographic image based on a result of detection of an interference light based on the scan signal light.