John Flannery
Professor of Neurobiology
Department of Molecular and Cell Biology
University of California, Berkeley

Each year many people lose their sight through disease of the retina, in these diseases, the cone and rod photoreceptors — the cells that convert light into neural signals — degenerate. And once these cells are lost, they are not replaced in the mammalian retina. For those who have already lost their sight, the possibilityof retinal transplantation using embryonic stem cells may be the best prospect for the restoration of vision.