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 ... more

Actually I really don’t know. But I fear that most of the time they only have some Ishihara plates to test colorblind persons. For proper testing you also would need some other tests like an University test for blue-yellow color blindness and of ... more

In this case you can compare it with near- or farsightedness. Some people have it, some not. Most people get farsighted when they get older but most important of all, it never causes pain. This is just what and how you can see, but it can never be ... more