Dr. David Berson

So you can see just by looking at a landscape, oh, it must be late in the day because things are looking golden.

That's all a function of our absorbing the light that's coming from the world and interpreting that with our brain because of the different composition of the light that's reaching our eyes.

I'm just kidding.

It's a great question.

It's a deep philosophical question.

It's a question that really probably can't even ultimately be answered.

by the usual empirical scientific processes, because it's really about an individual's experience.

What we can say is that the biological mechanisms that we think are important for seeing color, for example, seem to be very highly similar from one individual to the next, whether it be human beings or other animals.

And so we think that the physiological process looks very similar on the front end, but once you're at the level of perception or understanding or experience, that's something that's a little bit tougher to nail down with the sorts of scientific approaches that we approach biological vision with, let's say.

It's not really five types of cones.

There are really three types of cones.

And if you look at the way that color vision is thought to work, you can sort of see that it has to be three different signals.

There are a couple of other types of pigments.

One is really mostly for dim light vision.

When you're walking around in a moonless night and you're seeing things with very low light, that's the rod cell and that uses its own pigment.

And then there's another class of pigments we'll probably talk about a little bit later, this melanopsin pigment.

Right.

So in the case of a typical, well, let's put it this way, in human beings, most of us have three cone types and we can see colors that stem from that.

In most mammals, including your dog,

um or your cat there really are only two cone types and that limits the kind of vision that they can have in the domain of wavelength or color as you would say let's talk about the that odd photopigment