To measure the wavefront aberrations of human eyes, a Shack-Hartmann Sensor (SHS) was developed at UNAM-CCADET.
Usually, for calibrating the SHS a well corrected collimated beam is used, so the evaluation of the aberrations
depends on this calibration. We propose to use a Point Diffraction Interferometer (PDI) in parallel with the SHS, in order
to be able to check for aberrations in the calibration beam at any time. This allows reducing the delay between the
calibration and measurement of the aberrations of the eye made with the SHS. In addition, both measurements are made
without moving components, so the evaluation made through the SHS can be compensated with the reference beam
measurement made by the PDI. The results of the quantitative evaluation of the wavefront aberrations of a human eye are
presented in this paper.