still it would not be possible to discriminate if the green that i see is normal green or IR green. it would be rather obvious in the night, when color cones are not used, but during the day it would be confusing. I 'm thinking "Aww that s a beautiful tree ... oh , it's a trash fire"

No, that's exactly what the monkeys learned to discriminate. After a few weeks they pass monkey-specific colour-blindness tests, which wild-type monkeys cannot.

I don't think you are born with different wiring to the three different kinds of cones, your brain just learns to lump all the red ones together, so that a red object stays the same colour in different parts of your visual field. The claim is that the monkeys learned which of the previously-identical cones now had a new colour.

yes it is possible to create objects that can discriminate between colorblind and wild type. but from the point of view of the colorblind person (the augmented person) it will still be a source of confusion.

Just to be clear, the point isn't that we can distinguish which monkeys are treated, it's that the monkeys can distinguish many colours which they could not before. The treated ones behave like trichromats.

Do they lose any sleep philosophising about how these new colours are possible, and what to call them? Who knows. But I believe they can still do all the usual monkey things.

> it's that the monkeys can distinguish many colours which they could not before

That's the point they can not distinguish more colors. Their retinal cones still have the same spectral response. They cannot distinguish between a normal 500nm green leaf and a 900nm infrared source.

Ah, you mean the mice? In the near-IR study it's not clear (to me, yet) whether all the cones are altered, or just some of them. If all of them are altered, then for sure, same N=2 as normal mice.

The monkeys are in a different study, the one I linked a few posts above.

sorry i was referring to the nanoparticles. Indeed rhodopsins are used so routinely in neuroscience that one wonders why it has not been used to treat colorblindness in humans yet.

OK! I was told was that inserting genes with a virus like this had a tendency to cause cancer, which is why it wasn't done on humans (least of all for something not life-threatening). But I don't know if that is still accurate.

The nanoparticles sound to me like they could be safer? Would be interesting to know whether they can be non-uniformly spread, so that only half the green cones can see one.

I don't know enough about the subject matter to judge if this comment is correct or not, but it is polite, on-topic, and therefore shouldn't be downvoted.