Continuing Thoughts On Vision

Yesterday I discussed sight - vision more specifically whirling around color. Today I'm continuing that thought with general sight and vision. More specifically, how the environment is perceived by different species.

Dogs are missing the red/green spectrum, so their
vision is similar to some forms of human color blindness. 

The dog's vision as diagrammed above should look vaguely familiar to those who read yesterday's post about color blindness. In some ways, your dog sees very similarly to some forms of human color blindness - missing the red/green portions of the spectrum. There's still plenty of depth perception, but it's also one good reason why many breeds of dog are scent driven instead of visual hunters.

Cat's don't have a deep color sense, but that night
vision! OMG! So wonderful! 

How about our other major domestic companion - the cat? Cats are also missing a lot of the components that allow humans to see such a deep spectrum of colors, but their night vision - that's wonderful and deep. Where a human will stumble around in the dark, the cat sees all.

Bees see more into the ultraviolet, but less into the red. Take
a look at the next two pictures for what bees see. So wonderful! 

Bees see into the ultraviolet, but lose some of the red spectrum. What really interests me is that bees also see the electrical field generated by the flowers they prefer. In addition, the flowers themselves have developed patterns that extend into the ultraviolet and aren't perceptible by we lowly humans. The flowers need the bees, so they have an additional and more alluring raiment than what people can perceive.

Bees actually see the electrical field of their flowers. Just
look at that lovely and specific three points of focus for the
flower on the left. The flowers on the right show the ultraviolet
patterns and colors of the flowers that the bee perceives. 

Here, the flower on the right is how the bee would see this
lovely bloom. That total change of color that becomes visible
in the ultraviolet is pretty nifty. 

There's so much more written about vision out there. (Want a quick article? Just follow this link.) Some snakes have a special receptor allowing them to see into the infrared - heat sensing. Some deep water fish can actually see into the red spectrum and scientists question why, since red is a color that rarely appears at those depths. My question becomes, "If our world is visited/was visited by alien races from other worlds, what did the visitors see? How did they perceive our world?" So many books are written that center around interactions between alien beings and humans, but would that even be possible? How would we perceive each other? Have a wonderful Friday!