An optical image measuring device which can form a highly reliable image even if an object moves during scanning of a signal light is provided. An optical image forming device 1 comprises: an interferometer that splits a low coherence light L0 into a signal light LS and a reference light LR and generates an interference light LC by overlaying the signal light LS reflected by a fundus oculi with the reference light LR reflected by a reference mirror 14; a CCD 34 which receives the interference light LC and outputs a detection signal; Galvanometer mirrors 22 and 23 to scan the signal light LS in a main scanning direction and a sub-scanning direction; and a computer 40 forming tomographic images G1 to Gm along the main scanning direction at different positions of the sub-scanning direction. The Galvanometer mirrors 22 and 23 scan the signal light LS in a given direction crossing the main scanning direction, and the computer 40 forms a tomographic image for correction GR along the given direction to correct displacement of each topographic image Gi based on the tomographic image for correction GR.