A first illuminating optical system illuminates an eye with a wide beam. A first light receiving unit receives reflection light fluxes from the eye that have been converted into at least 17 beams by a first conversion member. A first compensation optical unit, disposed in the first illuminating optical system, compensates an illuminating light flux to the eye for aberration. A second compensation optical unit, disposed in a first light receiving optical system, compensates a reflection light flux from the eye for aberration. An operation unit determines, based on an output from the first light receiving unit, a compensation amount for cancelling out aberration to deform the first and second compensation optical units and compensate for aberration. The operation unit determines the optical characteristics of the eye, based on an output from the first light receiving unit after compensation, and on compensated optical characteristics.