Provided is a three-dimensional retina image generator that can detect, in a precise manner, the scanning position displacement during scanning of the retina with a simple configuration and, as a result, and can obtain a high-quality retinal image with a reduced influence of speckle noise therein. In order to detect the movement of retina R, the three-dimensional retina image generator has: second light source unit 210 that outputs a line beam to be imaged on retina R; positional displacement detector 220 that detects the line beam reflected from retina R and that detects the “displacement” of the scanning position during scanning of retina R; and dichroic mirror 230 that causes the line beam to propagate along the same light path as that of the object light scanning beam in inspection unit 140.