All degenerative retinal diseases are incurable by current methods. Retinal transplantation is a new experimental methodology that shows immense therapeutic potential for retinal degenerations. It remains to be established if functional connections are formed with the host visual system and if treated animals see better. This project will evaluate visual function in rodents with hereditary retinal degenerations that have received transplants. Royal College of Surgeons (RCS) rats will receive subretinal (SR) injections of retinal epithelial (RPE) cells while mutant mice (rd) will receive SR photoreceptors. Contralateral eyes will serve as controls. Graft function will be tested using the pupillary light reflex and the electroretinogram. Affiliated studies in the same laboratory will investigate central visual correlates of visual function using electrophysiological and behavioral methods. Taken together, these projects represent the most in-depth inquiry into the visual benefits of retinal transplants to date, and the first direct comparison of these two important rodent models.