Increasing numbers of corneal transplants for visual rehabilitation are being performed in the United States. The adequacy of visual function in these patients has been assessed only in terms of visual acuity, yet the importance of non-acuity parameters in real-world visual function is increasingly apparent. The specific aim of this proposal is to establish the effect of corneal transplantation on contrast sensitivity function and to determine the role of contrast sensitivity in the visual performance of transplant patients. The proposed method includes the use of an automated testing system of computer generated spatial frequencies as well as a non-automated chart system of measurement of contrast sensitivity. These tests will be applied to a controlled population of conreal transplant patients with good Snellen acuities. The pilot data gathered from this study, if positive, will serve as the basis for extending these investigations beyond the scope of this study to an assessment of real-world visual function in a variety of corneal diseases as well as in the burgeoning repertoire of surgical alterations of the anterior segment.