We will be evaluating the effects of the refractive keratoplasty procedres (Keratophakia, epikeratophakia, hypermetropic keratomileusis, muopic keratomileusis, radial keratotomy) in cainines and baboons. The animals will be evaluated preoperatively with cycloplegic refractions, corneascope documentation and will be photographed postoperatively on a regular basis until 2 or 6 months has elapsed. At the time of termination of the experiments, the animals will undergo a repeat cycloplegic refraction and corneascope photography. The eyes will be enucleated and the anterior segments will be evaluated with light, scanning and transmission electron microscopy. A computer program is used before every case to ascertain how much correction can be obtained. The clinical resuts will be compared with the calculated preoperative corrections so that the computer formulae can be evaluated for its predictability. We will attempt to correlate changes in corneal curvature with changes in refraction, but more importantly we will try to determine how to preselect a candidate who will response predictably. An analysis of our experimental data should provide an adequate assessment of the potential complications of the refractive corneal surgical procedures.