he's walking through the course, stepping over an object jutting in his path, avoiding the observe strackles, can have -- obstacles, confident and makes it to the end of the path without any problem whatsoever. how does this translate to daily life? this is what is so fantastic. this child who came in walking with a gain is riding bicycles, on a championship little league team, hammering objects, playing video games, hitting targets with rocks, maybe doing things his parents would rather him not do but leading the life of a normal child. >> charlie: what we want wie all want to know is to whom is that treatment going to help? what kind of blindness? >> this treatment will be effective for individuals who have mutations in the rpe65 gene because that is the type of dna that is delivered into the cells. if they have a mutation in a different gene, that wouldn't be effective. however, the exciting thing is that the same sort of approach can be used to intervene with other diseases that are due to other mutations and there are now at least a dozen other targets out there, several of which are no