No stereo vision but I can see the 3D effect in 3D movies ??
I had a turn in my eyes when young - an attempt was made to correct this with glasses, which was not fully successful. I've had no surgery, and still have eyes which look at different points.
I can't see the 3D images in the Magic Eye books, I have trouble parallel parking, and I gave up flying a paraglider partly because I was so nervous flying with others (not being able to judge my position in the air in relation to them), and so bad at judging where I was going to land.
But last year I asked my optometrist to give me glasses which would force both eyes to focus on the same point. He was very sceptical they would do anything for me, and repeated the line that 'the brain can't process stereo information as an adult if you couldn't as a child'. I've also been doing some work myself with the Brock string and red-green filters. But as far as I could tell I'd been making no progress towards stereo vision.
Then a couple of weeks ago I took my son to see a 3D movie. I put the 3D glasses on over my eyeglasses, and to my surprise I saw the movie in 3D (it was 'Puss in Boots').
I don't understand why I can see a movie in 3D, but not real life. I assume a 3D movie is not 'real' 3D and somehow I can see it. Or, it may be a sign I am getting some stereo vision?
If anyone has explanations or similar experiences I'd love to hear them.
Tags: 3D, movies, stereo, vision
Views: 1017
Replies to This Discussion
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Permalink Reply by Emanuele Ziglioli -
The book EyeTricks I've ordered has just arrived!
About 200 pages of hi-res stereograms, yum!
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Permalink Reply by Naoise McMullin -
I have had similar experiences looking at red-cyan anaglylph pictures, so I agree with you that it can't be (just) the alternating image technology used by some 3d films (and I too see the stuff coming out of the screen). In every case that I see here and have read of elsewhere, what people saw 3d were things either quite close or coming towards them. If it were a matter of alternating image projection, why would one not see distant things as well? The first things one sees in 3d are things close. It is true that in both film and photographs, people often exaggerate the effect by making the distance between the cameras (and hence the images registered) greater than normal human eye distance. This exaggeration makes near things seem much nearer than they "really are" and that helps those of us who don't see the normal 3d to see the effect.
But why would we see things close (and exaggeratedly close), first, and not other things? I don't really know, but I have noticed in other experiences and experiments I did, that I was first able to fuse two pictures, where they overlapped on the nasal side of the weaker/amblyopic eye. For some reason, the eyes get stronger on the nasal side first, with suppression still predominating on the temporal side. (In case you're unfamiliar with the jargon: nasal = nose; temporal = temple, ie to the ear side). Thus when we first experience 3d, it is when the amblyopic eye sees on the nasal side when the strong eye sees the whole field. This is almost equivalent to the eyes being crossed, which is how they are able to pick up the projected images that seem near. It may also be that for those of us whose weak eye also turns in, this too "helps". (If you look closely at an a good anaglyph picture, you will see that the respective images for left and right eye of a "pop-out" object are on the other side from the eye, that is, the image for the left eye is to the right of the image for the left eye. But the images for non-pop-out and farther back objects are on the same side as the eye. Thus an amblyopic eye can see the image on the other side ( the crossed image), but not see the images on the same side
And yes, there's nothing wrong with the brain cells, just the connections need to be used and strengthened. By repeatedly looking at anaglyph pictures, and pushing myself to see things a bit farther back, I was able to improve. I like what you said about seeing things solide and seeing the spaces; I don't think I ever do that.
Below is a red-cyan anaglyph image from flickr (thanks flickr people!). In the red-cyan glasses, red is over the left eye and cyan over the right eye. I'm not exactly sure how the technology works, but it seems to me that the opposite colour is transparent or doesn't register, so the left/red eye doesn't see the cyan part of the image, and vice versa. That means, it does see its colour. If you look at the cannon, the front of the barrel pops out of the image plane. Now look at the picture without the glaseses and note how the cyan image (what right eye sees) is to the left of the red image (what the left eyes sees). Compare this to the background, where the colour position is reversed.
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Permalink Reply by Andy -
Interesting - it could be down to a favourable convergence point in our mis-aligned eyes' view? I remember reading something about the Brock string exercise (In fact I think Sue wrote it) that there is a point some distance from the nose where the two eyes can work together at their easiest. This would explain why I can see 3d anaglyph well on my computer monitor, but if I look closer or much further away the effect dies. So if you can train your eyes to see anaglyph's further away, this is effectly vision training?
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Permalink Reply by Naoise McMullin
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Well, I don't know re Brock string; as I tend not to use it. Basically I'm less interested in the idea of "binocular posture" in terms of each eye mechanically pointing at the same spot in space. I think the more important thing is that both eyes and parts of the brain, etc. are "looking at" the same object or image, in terms of attention, or let's say in terms of mental focus. I like the stereograms and anaglyph photos because they put the emphasis on the same image, rather than on the same point in space (and of course they're more interesting). I think the brock string can help refine or develop one's ability to see stereoptically at a detailed level, and perhaps for developing divergence skills, but one can use other things for this too, eg stereograms place farther and farther apart (and anaglyph pictures showing things farther away, etc), and using either sort of picture with finer detail (eg an insects legs in relationship to a twig, as in the grasshopper picture) and learn to focus one's attention to such detail. But I think fixating on fine detail will actually prevent one from being able to fuse images at a grosser scale, where the respective parts of each image appear farther apart, the farther back in space the objects are (see the anaglyph picture below).
I'm going to go further on the nasal idea, as I've realized that even people whose eyes diverge (exotropes), tend to (and perhaps only do--- a study should be done on this) fuse first for close-up objects or stereograms showing things popping-out, etc. That suggests pretty strongly that it is nasal fusion rather than eye direction that is the key factor. I've noticed this unbalanced or lopsided fusion when looking at two graphics for flat fusion. When I look at the graphic pair below, I do see a fused image, but it involves gaps or blank areas for the left eye's view (my right is amblyopic at near distances). I am able to see the elements on the left side of the right eye's field of view (the nasal side), but not see or poorly/vaguely see elements on the right side (temporal side). There is of course the "physiological scotoma" (aka natural blindspot) on the temporal side in each eye (ca 10 deg from centre, ca 4 deg in diameter), which may be involved to some degree, but the perceptual scotoma or blank area seems much larger. Still, having a blindspot on the temporal side may make the temporal side less strong than the nasal side even in good vision.
When I said "closer" and "nearer", I meant in the pictorial space, whereas you seem to mean how far you are from the screen or picture. That's a good point too, as the effect of something "popping out" will be less the farther away one is, and more the closer one is, up to a point. It would seem that the thing appears near or far in relation to the picture plane; so if in a cinema one sat say 10 meters away, then something "popping out" (or seeming to zoom out towards one, as invariably happens in any 3d film with the trailers and ads at beginning) would "pop out" more and seem to come very close. Whereas, if one sat say 30 meters away, the effect would still be there, but less pronounced. So for anyone who have a hard time seeing any of these effects, sitting close to the screen should help one at least experience the effect as such. But this would depend on whether one does in fact have some central field fusion. You also have to go to the kind of films that have stuff zooming out (take a kid to a show?). "Grown up" films don't have much of that.
So if you can train your eyes to see anaglyph's further away, this is effectively vision training?
I should think so. Here's another anaglyph photo, showing what happens when things are farther and farther away in picture space. Look at how the railway lines split apart, the one seen by the left eye angles away to the left; the one seen by the right eye to the right. Also look at how far apart the respective images of the signal/barriers are on the left and the right. To fuse such an image, one has to be able to see the whole image for each eye at the same time. If half the field of one eye is blank/suppressed, you will not be able to see the effect. I can fuse the whole thing, but it is still weak perceptually to see the track "stretching into the distance." The barriers do seem farther away, but only when I pay attention to the stuff in between too. Then I get a sense of actual distance to the barrier. (After that the scene is flat, without any sense of the mountains off in the far distance.) But it goes to show that one's abilities can be developped; and that one can and should start with things coming out towards one, then seeing finer gradations of that (ie coming out a bit), with everything else as the same undifferentiated flat background. Then one looks at photos that have things "behind" the screen and tries to fuse and see/sense that. And of course the same goes for films, though one has fewer options and no control over what to work on.
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Permalink Reply by Emanuele Ziglioli
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@Naoise
The first things one sees in 3d are things close. It is true that in both film and photographs, people often exaggerate the effect by making the distance between the cameras (and hence the images registered) greater than normal human eye distance. This exaggeration makes near things seem much nearer than they "really are" and that helps those of us who don't see the normal 3d to see the effect.
That sounds about right, I've read movies don't require very fine stereopsis in order to perceive close objects.
But why would we see things close (and exaggeratedly close), first, and not other things? I don't really know, but I have noticed in other experiences and experiments I did, that I was first able to fuse two pictures, where they overlapped on the nasal side of the weaker/amblyopic eye. For some reason, the eyes get stronger on the nasal side first, with suppression still predominating on the temporal side. (In case you're unfamiliar with the jargon: nasal = nose; temporal = temple, ie to the ear side). Thus when we first experience 3d, it is when the amblyopic eye sees on the nasal side when the strong eye sees the whole field. This is almost equivalent to the eyes being crossed, which is how they are able to pick up the projected images that seem near.
This is a really good idea, I agree: I tend to look to my right (with left eye being the amblyopic one). But with object array stereograms, I do get a feeling of depth (or various levels of depth) not just right, but also left, up and down. I'm staring just a few cms from the page.
It may also be that for those of us whose weak eye also turns in, this too "helps". (If you look closely at an a good anaglyph picture, you will see that the respective images for left and right eye of a "pop-out" object are on the other side from the eye, that is, the image for the left eye is to the right of the image for the left eye. But the images for non-pop-out and farther back objects are on the same side as the eye. Thus an amblyopic eye can see the image on the other side ( the crossed image), but not see the images on the same side
I think you're right too. When I watch 3D videos with polarized lenses, I see objects coming out of the screen but not much the objects into the screen.
And yes, there's nothing wrong with the brain cells, just the connections need to be used and strengthened. By repeatedly looking at anaglyph pictures, and pushing myself to see things a bit farther back, I was able to improve. I like what you said about seeing things solide and seeing the spaces; I don't think I ever do that.
So, what's your verdict on stereograms as a tool for VT. According to Brock, stereograms would promote binocular posture, so they should be used first and before anti-suppression therapy. Sensory fusion (even partial) as an aid to motor fusion, and not the opposite as many OTs suggest.
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Permalink Reply by Naoise McMullin
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I haven't read about "sensory fusion" vs "motor fusion", sounds interesting. I gather from Sue Barry's article on Brock that he advocated real images or things that corresponded more to real life vision, and that certainly makes sense to me. But one often needs to use artificial things in order to analyze a problem and work on it. One can fuse a picture, for example, and have no idea that one is suppressing a big part of one eye's view or seeing it only to a degree, etc. But I think one should use whatever helps, whoever says what.
I prefer stereograms precisely because the eyes are looking at the same thing (or more or less; one needs differences in order to tell if each eye is looking and how well), rather than at the same point in space. Two pictures and hence two spots in space; but one object or scene. There is a sort of pre-existing unity, that involves the object of one's gaze, rather than the optical point of convergence. Also it seems alot more natural. But I think one does need to develop an amblyopic eye quite a bit before attempting to use it along with the strong eye, otherwise it won't be able to see anything. An amblyopic eye is often pretty "lazy" in being able to see even when the other eye is covered, so perhaps that's what the motor fusion people are concerned about. A weak eye that can't see well on its own, doesn't have a hope with the dominant eye there too. Go to the gym before getting out into the ring.
I am still curious about why and even how you look at these object array stereograms from so close. Couldn't you move back a bit and actually see the images clearly? When I spoke of "soft focus", I meant it as in "soft eyes" (google this with martial arts, esp aikido), that is, pulling back from being so focussed mentally on detail and acuity, in order to see over a wider area. But when one does see over a wider area, one sees clearly, not in a defocussed way. Greg Voth talked about his peripheral vision being "tack sharp" and that sounds like the right idea. I don't know about "peripheral", as what interests me more here is the area of the central field, which is where true stereopsis takes place. But the main thing is that one needs to make a distinction between clarity and acuity. One can see clearly, without seeing acutely; one does not need to or want to see fuzzily or vaguely, just not acutely. One needs to shift something in the mind, not in the eyes; so one looks broadly and clearly, rather than narrowly and acutely.
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Permalink Reply by Emanuele Ziglioli
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Hi Naoise
I haven't read about "sensory fusion" vs "motor fusion", sounds interesting. I gather from Sue Barry's article on Brock that he advocated real images or things that corresponded more to real life vision, and that certainly makes sense to me.
about motor and sensory fusion, have your seen these lectures: http://arapaho.nsuok.edu/~salmonto/vs3.html
But one often needs to use artificial things in order to analyze a problem and work on it. One can fuse a picture, for example, and have no idea that one is suppressing a big part of one eye's view or seeing it only to a degree, etc. But I think one should use whatever helps, whoever says what.
As a kid they made me put a lion in the cage, which I found impossible because my left eye kept jumping. That was an exercise of flat fusion with unrealistic images (drawings). Sharp borders trigger strabismus, that's why I soft focus and only then images are stable, with the benefit of depth perception (in the case of stereograms).
I prefer stereograms precisely because the eyes are looking at the same thing (or more or less; one needs differences in order to tell if each eye is looking and how well), rather than at the same point in space. Two pictures and hence two spots in space; but one object or scene. There is a sort of pre-existing unity, that involves the object of one's gaze, rather than the optical point of convergence. Also it seems alot more natural. But I think one does need to develop an amblyopic eye quite a bit before attempting to use it along with the strong eye, otherwise it won't be able to see anything. An amblyopic eye is often pretty "lazy" in being able to see even when the other eye is covered, so perhaps that's what the motor fusion people are concerned about. A weak eye that can't see well on its own, doesn't have a hope with the dominant eye there too. Go to the gym before getting out into the ring.
Well, let me explain briefly how I think my eyes work. Due to the surgery I had as a kid, my eyes look straight most of the time. What happens though is that vision though my left eye is blurry/defocused, and that seems to help my brain to suppress it.
If I cover my right dominant fovea, and I focus through my left eye, I get a sharp, high constrast picture but my right eye turns in quite badly. So my starting point is with my eyes looking in the distance, that's when I get a chance for fusion. I hope I can train my brain not to overconverge my eyes as I focus more and more. With stereograms and depth perception I get a feedback on when my eyes are locked into binocular posture.
I am still curious about why and even how you look at these object array stereograms from so close. Couldn't you move back a bit and actually see the images clearly? When I spoke of "soft focus", I meant it as in "soft eyes" (google this with martial arts, esp aikido), that is, pulling back from being so focussed mentally on detail and acuity, in order to see over a wider area. But when one does see over a wider area, one sees clearly, not in a defocussed way. Greg Voth talked about his peripheral vision being "tack sharp" and that sounds like the right idea. I don't know about "peripheral", as what interests me more here is the area of the central field, which is where true stereopsis takes place. But the main thing is that one needs to make a distinction between clarity and acuity. One can see clearly, without seeing acutely; one does not need to or want to see fuzzily or vaguely, just not acutely. One needs to shift something in the mind, not in the eyes; so one looks broadly and clearly, rather than narrowly and acutely.
Well, I'm not yet able to understand deeply what you see and mean.
Simply, I think when I Iook very close, my peripheral vision helps my central vision into binocular posture. Because of what I wrote above, the images don't have clear borders, when I try to focus, I overconverge.
As I move away, my left eye also struggles to follow until I loose binocular posture and I see flat. My aim though is to keep exercising and look at stereograms from a further distance.
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