PROBLEM TO BE SOLVED: To reduce time based on feedback control required until the amount of proper aberration correction is reached, when a position of a specimen to be measured is changed.SOLUTION: An imaging device performs feedback control for repeating detection of wave aberration of a subjects eye on the basis of a detection signal from a wave front sensor and control of a wavefront compensation device on the basis of the result of the detection, and temporarily stops the feedback control and restarts the feedback control, on the basis of the detection signal from the wave front sensor.SELECTED DRAWING: Figure 5