Device for measuring aberrations in an eye includes, an illumination path with an illumination diaphragm and a test path, imaging member and elements for positioning the eye in relation to the imaging member, a stray reflection filter element, which is centered on the measurement axis of the imaging member, and elements for the optical conjugation of the pupil of the eye with the plane of the illumination diaphragm and the test plane. The illumination beam path converges at the center of the filtration element. The filtration element, the illumination path, the test path and the conjugation elements are all interdependent and positioned on a platform that can move in relation to the imaging member along the axis. The illumination diaphragm is off-center in relation to the axis such that stray light flux reflected by the imaging member is deflected from the test path by filtration element.