An adaptive optics system includes a spatial light modulator configured to spatially modulate a phase of an optical image incident on a modulation surface including N two-dimensionally arranged regions and a wavefront sensor including a lens array having N two-dimensionally arranged lenses corresponding to the N regions and an optical detection element for detecting a light intensity distribution including K converging spots formed by the lens array and configured to receive the optical image after the modulation from the spatial light modulator, wherein a correspondence relation between the region of the spatial light modulator and the converging spot formed in the wavefront sensor is specified.