And there are other constraints, too. UV is blocked by water (and our lens material) and can induce chemical changes (read: damage) easier than visible light. Damaging sensitive retina. Not that this is an unsolvable problem (bees see UV), but it is a biochemical constraint. Infrared, especially far infrared, doesn't work too well without a cooled sensor. And the energy per quanta is less, which reduces your options for good, high-sensitivity biomolecules that can detect them, kind of the opposite problem of UV.
So yeah, there are a few reasons why visible light is visible light and why we can't see UV or infrared. It's not entirely arbitrary or random. But "seeing" with sound is also a viable evolutionary approach, but less effective in a low-density medium like air and more effective (even than light) in a medium like water.
> Visible is pretty smack dab in the middle of the Sun's peak spectrum...
Does this mean that our vision system evolved to pick up the most energetic part of the Sun's spectrum that ends up at the surface? Did it evolve this way so our vision systems' cellular agglomerate don't have to expend as much energy gathering that part of the spectrum as opposed to other parts of the spectrum?
If so, then is there any linkage via evolutionary theory that imply our vision system might be among the first vision systems to evolve on the planet, because it filled the most-favored evolutionary niche associated with the lowest energy expenditure to gain a evolutionarily competitive advantage over other pre-human species?
I would point out that the crystal field splitting energies happen to correspond to the region around visible light, which means that being able to finely distinguish gradations of visible light would lead you to be able to visually distinguish between many different organometallic ions. I suspect that matters more than the flux of visible light in the solar spectrum.
And there are other constraints, too. UV is blocked by water (and our lens material) and can induce chemical changes (read: damage) easier than visible light. Damaging sensitive retina. Not that this is an unsolvable problem (bees see UV), but it is a biochemical constraint. Infrared, especially far infrared, doesn't work too well without a cooled sensor. And the energy per quanta is less, which reduces your options for good, high-sensitivity biomolecules that can detect them, kind of the opposite problem of UV.
So yeah, there are a few reasons why visible light is visible light and why we can't see UV or infrared. It's not entirely arbitrary or random. But "seeing" with sound is also a viable evolutionary approach, but less effective in a low-density medium like air and more effective (even than light) in a medium like water.