This report describes the gross and microscopic changes induced by the laser beam in two human eyes. To our knowledge this is the first such description in the medical literature. The two eyes were to be enucleated for malignant melanoma. Therefore, with the permission of the patients, the retina of each eye was exposed to laser energies, as if the retina were being treated for a retinal tear, to study pathologically the lesions obtained; and the melanomas were exposed to maximum laser energies with the laser photocoagulator previously described1-3 to determine what effect, if any, such energy levels would have upon the tumors. Report of Cases Case 1. —The patient was a 57-year-old white man who was found on routine eye examination to have a pigmented mass in the right eye involving about one half of the surface of the iris with numerous extensions into the angle of the