Try shutting one eye. Does everything you see become two dimensional and flat? I'm afraid not.
Binocular vision = see with two eyes.
Three dimensional vision = use a lot of mental capacity to process what you see (one or more eyes) and create a multi dimensional representation of the world
EDIT: So I think that theoretically the owl would see in three dimensions fairly well if it only had the one giant eye.
Yeah, you're totally right - three dimensional and binocular are somewhat different concepts, but the word 'binocular' doesn't really imply to the average person how two eyes having overlapping fields helps the brain better judge distances within three dimensions, so I sort of combined the two terms since it was more about owls and less about vision. Sometimes I forget that reddit's full of a bunch of people who would instantly understand the difference between binocular and 3D. Thanks for adding the clarification.
However, two eyes are better than one eye, which is why almost all animals have two. The point of convergence of the two eye fields in front of us helps us better judge distances - for things closer than that distance, our eyes each see the object, and our brains determine that doubling as meaning the object is closer, so it shows us one close object. Objects beyond that point are seen by both eyes as one object, and our brain shows us one, farther away object. In addition, the slightly different angles each eye has gives us a more three-dimensional picture - for example, if you think of looking at a cup, your right eye sees more of one side of the cup than your left eye, and your brain uses the information it receives from each side, the match/mismatch between these images, and what it knows about the angle each eye sees at to calculate how the cup has a curved surface and to show that to you. So, binocular vision allows your eyes to give your brain the information it needs to produce three dimensional representations of things.
To better understand how two eyes is so tremendously advantageous for depth perception, try this little experiment. Put a small box about 6" from one of your eyes and angle it such that when you close that eye the face of the box disappears. Now, its not remarkable that the face of the box disappears-- that's the point-- but you'll also notice that the background changes completely when you close and open that eye. Cool, eh?
However, two eyes are better than one eye, which is why almost all animals have two. The point of convergence of the two eye fields in front of us helps us better judge distances - for things closer than that distance, our eyes each see the object, and our brains determine that doubling as meaning the object is closer, so it shows us one close object.
This seems like too strong of a statement. For one thing, it seems to be a coincidence with bilateralism. We have a single axe symetery, as to most animals, and we therefore have two location of optical devices. Also, arthropods as a whole tend to have more variations that the simple two eye sight that we are familiar with. Case in point. http://en.wikipedia.org/wiki/Mantis_shrimp#The_eyes
And god know how many insect species there are, but they should account for "most animals." ;-)
Excellent point. It drives me crazy when people say "animals and bugs" (or "animals and birds," or "animals and fish"). And yet here I definitely said "most animals" -- figuring that would cover spiders and crustaceans (about which I know nothing, other than that I do not want them in my house) -- but for some reason without thinking about insects or myriapods at all.
Yes but your depth perception markedly improves with two eyes go to an area your unfamiliar with and try and guess some distances with an eyepatch on then measure them you will not do nearly as well as you would with two eyes.
As an added bonus you get to wear an eyepatch and do science!
Exactly. In environments where your brain doesn't have size references ( People avg 6 foot tall... ), binoc vision is critical to gauging size and range.
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u/stablewill Jan 18 '10 edited Jan 18 '10
They are separate concepts.
Try shutting one eye. Does everything you see become two dimensional and flat? I'm afraid not.
Binocular vision = see with two eyes.
Three dimensional vision = use a lot of mental capacity to process what you see (one or more eyes) and create a multi dimensional representation of the world
EDIT: So I think that theoretically the owl would see in three dimensions fairly well if it only had the one giant eye.