PSF and MTF comparison of two different surface ablation techniques for laser visual correction

It is well known that the Zernike expansion of the wavefront aberrations has been extensively used to evaluate the performance of image forming optical systems(1). Recently, these techniques were adopted in the field of Ophthalmology to evaluate the objective performance of the human ocular system(2-7). We have been working in the characterization and evaluation of the performance of normal human eyes(8,9); i.e., eyes which do not require any refractive correction (20/20 visual acuity). These data provide us a reference model to analyze Pre- and Post-Operated results from eyes that have been subjected to laser refractive surgery. Two different ablation techniques are analyzed in this work. These techniques were designed to correct the typical refractive errors known as myopia, hyperopia, and presbyopia. When applied to the corneal surface, these techniques provide a focal shift and, in principle, an improvement of the visual performance. These features can be suitably described in terms of the PSF and MTF of the corresponding Pre- and Post-Operated wavefront aberrations. We show the preliminary results of our comparison.