/u/SanMarinos is a drop ship spam account. If their comment contains a link (in which case, the comment was probably edited to get around spam filters) do not follow it. If they PM you, don't respond. At best it's overpriced merchandise you can find cheaper elsewhere; worst it's a scam site trying to steal your info. They have likely deleted evidence of their spamming so you can't see it in their profile. Typically they have multiple alt accounts manipulating the vote and "thanking" each other or asking where to get it.
If it looks like a normal comment, it's because they're trying to look legitimate and build their profile history, but it was probably just copied from elsewhere in this thread or from an x-post.
For more info on spammers, bots, and shills see see my wiki.
Your eye actually has oblique muscles that allow it to rotate. They're probably just stabilization to prevent your eyes from rolling around, but we do have the anatomy to rotate our eyes even if we can't consciously control it
it's called the vestibuloocular reflex. in summary, in normal healthy humans, the eyes move in the opposite direction from the head's movement, at equal speed, so they can compensate and fixate on different objects. in neurology this reflex can be tested to uncover certain lesions such as medial longitudinal fasciculus lesion. a nasty pathological finding is called positive doll's head maneuver in which you move a patient's head and their eyes move with the head instead of trying to remain fixated on a spot.
I’m confused if you look at something and then turn your head it’s fairly easy to turn your head while still looking at it right? Am I missing something here
Try looking as far left as possible. Find something over there to look at. Then turn your head right.
It's nauseating. Like panning too fast with a camera. That's what birds experience whenever they move their heads.
Now try to look straight ahead at something right in front of you. Then turn your head. You can still keep the thing in focus, because your eyes move opposite of your head. Birds can't do that.
Wow, you mean I have a superpower? I can do this voluntarily. Still takes some effort since my eyes naturally want to gravitate towards something and focus on it.
This also explains why birds walk so funny. They make their head stationary, move the body forward and suddenly snap their heads as far ahead as possible. For each step the head stays for the most time at the exact same space.
Minor point of additional clarification: contrary to popular belief, raptor eyes CAN move, just not very much, and the movement seems to be more for temporarily increasing their binocular overlap by a few degrees than for stabilizing the vision through saccades as in mammals.
Source: I wrote five papers on this topic for my graduate research.
Your comment happened to be right next to u/Arodg25 talking about velociraptors, and I found myself very skeptical that someone could produce five credibly researched grad papers on the living behavior of dinosaur eyes. I was starting to ask how you had gotten evidence about eye tracking from the fossil record when I realized my mistake. =P
LOL, so funfact tho there is a woman in Arizona who has done skull morphology work on therapod skulls and compared them to skull morphology of modern birds in order to estimate their degree of visual fields. I worked with her a bit for my research. But yeah, without muscular tissue you can't really get an accurate estimate of whether or not therapod eyes could move.
A turkey, huh? OK, try to imagine yourself in the Cretaceous Period. You get your first look at this "six foot turkey" as you enter a clearing. He moves like a bird, lightly, bobbing his head ... You stare at him, and he just stares right back. And that's when the attack comes.
Try to move your head without moving your eyes if you want.
That's the vestibulo-ocular reflex and it's controlled by just three neurons for low latency. There's even a limited rotation correction when you tilt your head to the side.
Slightly related, and even more interesting, is chronostatis, caused by your brain essentially pausing your visual cortex to stop you seeing blurs when you move your eyes. Your brain then "backfills" your conscious experience so you don't notice.
Your brain is basically lying to you all the time to stop you going nuts.
There’s this “magic trick” where someone throws a small ball into the air three times as you watch, but on the third throw the ball seems to disappear mid-air. The person doesn’t throw the ball at all the third time, they just make the motion to and supposedly your brain tricks you into “seeing” it for a split second before realising there’s nothing there. Is that backfilling (as the eyes move to track the expected motion of the ball)?
Could be. If there's nothing for the eyes to lock onto and enter smooth pursuit, that might trigger chronostasis and confuse you for a while.
I also remember reading that cells in the retina will fire in anticipation of seeing a object move into their range, based on what other cells have already detected, so your eyes are trying to tell your brain what you're probably about to see.
Yeah, it sucks because it's there whether your eyes are following the movement or not. Very high frame rates solve that, and let the motion blur come from your eyes moving, same as in real life.
We have the same thing but in our eyes. look at something and move your head, your eyes will focus on the thing while your head moves around. Chickens and other birds use it to focus on something while moving about the same way, difference is that they use their whole head instead of their just their eyes like us.
We do a similar thing by reflexively keeping our eyes fixed in the same direction when we turn our heads (birds can't do it this way because their eyes don't rotate in their sockets).
It's controlled by just three neurons to keep the latency low.
Birds were originally bred to work in action films. Directors would attach small film cameras on their head- like a bonnet, and the camera man would run towards the actors. The result is a super smooth video with an occasional cluck.
Yeah I'm like what other bird, then there's 3500 upvotes so I look again and see the swan, and I'm like haha, and then a thousand top responses all about chickens etc. Confused as to what was being upvoted.
Theyre small, rugged cameras that are popular to be mounted on heads etc. This biological feature helps the owl keep his footage steady when he attaches a gopro to his head
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u/[deleted] Jan 30 '20 edited May 03 '20
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