Eugene Leitl wrote:
> CurtAdams@aol.com writes:
> > An extremely deep purple, flecked with transient green dots (which
> > come from fluorescence of optical pigments).
> According to some forgotten source (Stryer?) certain monkeys have a
> fourth color in the making, in a couple of megayears there could have
> been four-color vision primates. (Of course if there is a Singularity
> the Earth won't probably exist by then).
Deer see well into the ultraviolet, which is why deer hunting can be difficult and unrewarding to the novice, as common clothing detergents have color brightening dyes that make you look like a neon sign in ultraviolet. They can see you coming from a mile away. They only have yellow and blue cones in their eyes (no red cones) and they have no ultraviolet filter in the cornea (as is normal for humans), plus they have a reflective layer behind the receptors to reflect back through the cells light that passed through without reception.
I would imagine that people who claim to see auras actually have defective UV filters in their corneas....which could explain why people struck by lightning report such abilities after their electric experience, as the lightning bolt's high levels of UV emissions likely burns out some or all of the UV filters.