What has changed in the color perception of the monkeys?
Jay and Maureen Neitz explain it on their website as follows: Before the treatment the monkeys had only two perception patterns which could differentiate hues, S supported by M and M supported by S. The insertion of the third opsin gene gave rise to new color perception stimuli: M supported by L+S and L supported by M+S. Listen to the Interview with Jay Neitz on “Gene Therapy for Red-Green Color Blindness in Adult Primates” After a while the brain started to react on this new information. Gaining this new dimension of color vision becomes a simple matter of splitting the preexisting blue-yellow pathway into two systems, one for blue-yellow and a second for red-green color vision; which sounds almost to simple to be true. When will we be able to cure color vision deficiency? Nobody knows the answer on that question. But people like Jay Neitz think that this could get true in the near future. You shouldn’t be to optimistic yet as it still needs a lot of testing. First of all the proposed