An apparatus for motion compensated modelling of a parameter of an eye, comprising: a first measuring means for measuring a plurality of position parameters of the eye with respect to an optical reference coordinate system of the apparatus； a second measuring means for measuring an interference signal at a plurality of optical reference coordinates, wherein the measurement of the plurality of position parameters and measurement of the interference signal are time synchronised； means for correcting the interference signal to account for a displacements of a parameter of the plurality of position parameters ； and means for modelling the eye parameter based at least in part on the corrected interference signal.
