Question about eyes

robfosters

robfosters

robfosters

Caporegime
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Biology is not my strong point.

When we go boss eyed, our left eye looks right and our right eye looks left. Why cant our left eye look left while our right eye looks right?
 
normally in the animal kingdom prey animals have eyes on the sides of their head, maximum field of view for predators, indeed some can even see behind their head without turning.

predators have eyes like ours, two eyes in the front of the head for rangefinding, this is why cats eyes have elongated lenses to allow them to focus even more tightly.

now for humans and indeed monkeys, originally vegitarians [or at least omnivores with a heavily veg/fruit diet] we don't need to rangefind prey, but the ability to rangefind branches and such when swinging through the trees is very useful hence the predator esque eyes.

as zethor said, there's no evolutionary advantage for the 'prey' type of vision with eyes looking independantly as there arent many big predators in the trees hence it didn't evolve.
 
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robfosters said:
Yes but when we are boss eyed, aren't they working independently then?
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yes, but not to any advantage, like many things [such as heavy short sightedness] modern civilised life has allowed boss eyes to not be so much of an issue as to prevent you living a decent enough life.

in a survival of the fittest scenario it would be less than ideal.
 
OK, I'm with you on that one, but my argument still is, if there is no advantage to going boss eyed, why can we do it but not the other way. I may be being thick, but thats what I dont get, why can I look inwards independently but not outwards. What specifically is stopping me being able to do that?
 
adolf hamster said:
normally in the animal kingdom prey animals have eyes on the sides of their head, maximum field of view for predators, indeed some can even see behind their head without turning.

predators have eyes like ours, two eyes in the front of the head for rangefinding, this is why cats eyes have elongated lenses to allow them to focus even more tightly.

now for humans and indeed monkeys, originally vegitarians [or at least omnivores with a heavily veg/fruit diet] we don't need to rangefind prey, but the ability to rangefind branches and such when swinging through the trees is very useful hence the predator esque eyes.

as zethor said, there's no evolutionary advantage for the 'prey' type of vision with eyes looking independantly as there arent many big predators in the trees hence it didn't evolve.
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What a load of BULL.. I read a book and it doesn't mention anything about this evolution thing you speak of..........................oh hang on
 
robfosters said:
OK, I'm with you on that one, but my argument still is, if there is no advantage to going boss eyed, why can we do it but not the other way. I may be being thick, but thats what I dont get, why can I look inwards independently but not outwards. What specifically is stopping me being able to do that?
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Muscles, and brain capacity to process it. I assume when you look in, you have no proper sense of it. Just two over laying images that are extremely hard to process.
I can't look in, I can look out. Squint for you. (fixed through surgery, other than latent so when eye lids are shut they wonder)
 
robfosters said:
OK, I'm with you on that one, but my argument still is, if there is no advantage to going boss eyed, why can we do it but not the other way. I may be being thick, but thats what I dont get, why can I look inwards independently but not outwards. What specifically is stopping me being able to do that?
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Looking inwards is an integral part of rangefinding, both eyes looking straight forward for long distance, and crossing over at closer range.

By overlapping the images at different angles you can work out the range, for example old artillery scopes used to have far set apart lenses, like stretched binoculars, to increase the width to help with accuracy over long range.

Our ability to go cross eyed stems from manual control of existing programming if you get what i mean.
 
Doesn't have anything to do with range finding, your vision overlaps basically at the end of your nose, there's no need to go cross eyed at any range,
 
robfosters said:
OK, I'm with you on that one, but my argument still is, if there is no advantage to going boss eyed, why can we do it but not the other way. I may be being thick, but thats what I dont get, why can I look inwards independently but not outwards. What specifically is stopping me being able to do that?
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It's to do with focus. There is an advantage to being able to look inwards, that is being able to focus both eyes on something which is closer to your eyes. Hold your arm out at arms length and look at your fingertip. Then bring the finger closer to your eye. You will encounter a natural reason for your eyes to go inwards in order to maintain a visual lock. Now push your arm out again. your eyes will return to looking straight. If you keep pushing your arm out to infinity your eyes wont start looking outwards.

Technically our eyes are ALWAYS looking "inwards" because wherever we're looking we form a triangular shape between corner at the object. Your eyes are never "looking straight", they're always looking at an object, which means they always have to be looking inwards even if the object is very far away.
 
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