Something I've never understood

[Spinaroonie]

If you close one eye, you're supposed to lose depth perception. I've never really gotten it. If I close one of my eyes, I can tell which object is farther away or which is thicker or something.

I've never really gotten that.

 

[brokenbrainwave]

see you were that special boy we always were told about

 

[Gaultier]

try that "join your 2 fingers in mid air" with one and both eyes...and u should get it

 

[I'mVan]

try that "join your 2 fingers in mid air" with one and both eyes...and u should get it

Can do. it's possible to tell, because you have to change the shape of your cornia. However, it's not as effective as two eyes. Try throwing something, that might prove it.

 

[vffan]

I bet you can't do those 3-d pictures either. I know I can't. Can't do that "joining the two fingers" thing either.


J

 

[Spinaroonie]

I bet you can't do those 3-d pictures either. I know I can't. Can't do that "joining the two fingers" thing either.


J

I can even do "magic eye" to background images on websites, they get pretty trippy.

 

[seXieleXie]

If you close one eye, you're supposed to lose depth perception. I've never really gotten it. If I close one of my eyes, I can tell which object is farther away or which is thicker or something.

I've never really gotten that.

where did you hear/read that? it's not true.


okay, here's a cool thing to try. get a quarter, then stand across the room from a face clock or some other circular object. close one eye and line up the quarter so it totally covers whatever the circular object you are looking at. now move it slightly to one side.... which one looks bigger?

they are projecting images of exactly the same size on your retina, but you perceve the clock as bigger because it is farther away.

 

[Spinaroonie]

Re: Re: Something I've never understood

they are projecting images of exactly the same size on your retina, but you perceve the clock as bigger because it is farther away.

Right. I always thought that was because of all those art classes I took as a kid. Tuaght me about perspective and stuff.

 

[The Heretic]

try that "join your 2 fingers in mid air" with one and both eyes...and u should get it

Not a good test; I can do that with two eyes open, one eye open, and no eyes open - its called proprioception.

 

[peachykeen]

Binocular disparity is not the only means we have of depth perception, it's just one tool. Even though with one eye you are only seeing a two dimensional image, and therefore not actually 'seeing' depth, that doesn't mean you are not perceiving depth by other visual cues (ie linear perspective).

 

[claude_moveml]

Even with two eyes you are only seeing two two dimensional images, and therefore not actually 'seeing' depth, that doesn't mean you are not perceiving depth by other visual cues (ie parallax shift)

 

[peachykeen]

You're just following me around so you can stare at my ass, aren't you, you perv.

 

[Blindinthedark]

Spinaroonie:
A better test is to close one eye and have someone toss something at your face. Try to catch it. You'll notice the difference.

 

[claude_moveml]

Not guilty. No wait, guilty. No that doesn't work either. I'll go with the Scots with not proven, that ought to do it.

 

[TWB]

Do you have three eyes?

 

[CoolidgEffect]

Other depth cues include relative motion, parallax, relative size.

You can catch a ball with only one eye. The ball gets bigger as it approaches you and its motion is different from the background.

 

[Blindinthedark]

Other depth cues include relative motion, parallax, relative size.

You can catch a ball with only one eye. The ball gets bigger as it approaches you and its motion is different from the background.

You can catch the ball but it's much more difficult to do without binocular vision.

 

[curious2c]

try that "join your 2 fingers in mid air" with one and both eyes...and u should get it

OW...damn that hurt...I just poked my eye out...geez

 

[CoolidgEffect]

You can catch the ball but it's much more difficult to do without binocular vision.

Much more difficult in what what?

-------------------------------------------------------
Exp Brain Res 1998 Mar;119(1):92-102

Monocular and binocular control of human interceptive movements.

Servos P, Goodale MA.

Department of Psychology, University of Western Ontario, London, Canada.

Previous work in our laboratory has demonstrated that binocular vision makes an important contribution to skilled reaching and grasping movements directed at static targets. In the present study we examine the contribution of binocular vision to interceptive reaching movements. We monitored such movements using a high-resolution, opto-electronic recording device (WATSMART), while subjects attempted to catch balls projected at them. No differences were found between monocular and binocular viewing conditions using this paradigm - either with respect to the velocity profiles or trajectories of the reaches. Moreover, the grasp was not affected by the type of vision available. It appears, then, that the moving targets provide adequate monocular depth and direction information (on the basis of optic flow) for the control of skilled interceptive movements directed at them. In addition, the time to achieve maximum grip aperture was constant across the trials - a finding consistent with the use of a time-to-contact variable derived from optic flow information. Finally, the transport component of prehension was found to be affected by certain variables that have, in the past, been thought to exclusively affect the grasp component of prehension, whereas the grasp component of prehension was affected by factors that have traditionally been thought to affect only the transport component.