An apparatus and a method for refractive surgery, in particular LASIK, make provision whereby the apex of the cornea is taken as a basis, as the ablation center, for the refractive procedure. For this purpose, the dependence of the position of the apex on properties of the pupil is determined in the case of the eye to be treated and, from this dependence, measured properties of the pupil are used to calculate the position of the ablation center during the refractive surgery.