I have been trying to imagine what life would be like if humans had eyes on the sides of their heads like prey animals pretty much since we began our study of the eye. Obviously from a simple “predator/prey” point of view, it makes evolutionary sense to have our eyes on the front of our heads rather than the sides, but given our extreme dominance on the food chain, if we now had the choice, which of the configurations would we choose? From an aesthetic point of view, it would be ridiculous looking for a person to have eyes on the sides of their head rather than on the front of their face, but looks aside (no pun intended), would humans benefit from having eyes on the sides of their heads?
For the most part, humans are untouchable on this planet in terms of evolutionary dominance. There is not even the slightest chance of our being challenged by anything else for control of the food chain, so thinking of us as either a predatory animal or a prey animal doesn’t really matter. My question, is what would life be like with eyes on the side of our head, and if we were able to choose, would our visual life be richer or more useful if our eyes were moved to the sides of our heads, rather than the front? The negatives of having eyes on the sides of our heads seem clear: a significant decrease in binocular vision; however, I think that the benefits of having eyes on the sides of our heads outweigh this negative. Animals with eyes on the sides of their heads simply see much more of the world. Think about how hard it is to sneak up on a rabbit. Because they can see much more of the world around them, it’s nearly impossible to get to them without you knowing that they’re coming. Now think about how many car accidents are caused every year by people who do not see cars that are in their “blind spot,” with eyes on the side of your head you would be well aware of the other car and would not get into one of those accidents. While the loss of binocular vision is a concern, we look at everything we pay attention to straight on. Think about reading this blog entry. You are staring straight at the screen, and while you are able to see the 3D form of the water bottle sitting to the right of your computer, if you are going to pick it up, you are going to look directly at it before you try to grab it (in most cases). My point is that the objects its most important to see with binocular vision are objects that we are staring straight at, and with eyes on the sides of our heads, we would still have binocular vision for these objects. I do not know what living with eyes on the side of my head would be like, and I probably never will. From an evolutionary standpoint it makes sense for us to have our eyes positioned where they are, but from a conceptual position, I wonder if we wouldn’t now, all other things remaining constant, be better off with eyes on the sides of our heads.
April 20, 2008
