also joining me, jean bennett, steven schwartz, eberhart zrenner, and carla shatz of stanford university and once again, eric kandel a nobel laureate and a howard hughes medical investigator. i began with my friend eric to give me an overview of our subject tonight. >> the last program we did was approaches to deafness. tonight we are going to consider new approaches to the problem of blindness. as is the case with deafness, blindness is not a life threatening situation but it is disabling. in some ways it is more disabling than deafness because there are a number of important conditions for which there is no treatment. now, why is that so? unlike deafness, the sensory organ for vision, the retina, which is evident in the lower image, it lines the inside surface of the eye. that is the most complex set of organs we have. in fact, it is not a proof real organ. it is actually a part of the central nervous system. as a result, it has the complexity of the structure. it is not uniform. it has a small area that is clear which is called the macula. it is the area of greatest visual acuity. so

and i think, as jean and eberhart pointed out, it's really the team. i could not do this myself. for the future, efforts like what you do, this great work, allows people to understand the suffering, what sandy has gone through and the countless number of people who go blind unnecessarily, bringing blindness to the forefront and ending it is what my goal is as a treating physician, and macular degeneration, whether gene therapy or stem cell therapy or a chip, would be a great thing to knock off the podium as sort of the leader of blindness. >> charlie: well said. we have so far about 40 patients, and it doesn't work in all of them. some have very degenerated retina and we have to understand only half of the patients have useful vision in daily life. but there are more than 30 groups working worldwide on those approaches, some in the united states on the cell side, the others the brain. for patients like sandy who have lost the optic nerve or other people who have lost the eye, it is possible to directly connect implants to the brain. that may be a way to help the other patients wh