I'm 15 months in VT to see in 3D and I need some psychological encouragement. For those who are not into "New Age" thought, this may seem esoteric to you, but the power of the mind is vast and I want to use positive thinking to get me to seeing with both eyes and fusing.
I'm reading the book, "Power" by Rhonda Byrne. It's the sequel to the international bestseller, "The Secret" which was also an Internet movie hit. For those not familiar with "The Secret" and "The Law of Attraction", the basic premise is that to bring something into one's life, one has to imagine that he/she already has it, feel that he/she has it and believe that he/she has it. "Like attracts like" so you have to be on the same vibration of what you want in order for it to come to you. If you want a new car, you imagine what it looks like, you feel what it's like to drive it and you believe you really own it. Only thinking about not having something, like I do about 3D, is not getting me closer to having stereopsis because it only makes me more anxious, frustrated, etc.
Visualization is a key tool for the law of attraction, but those of us who are stereoblind can't visualize something we are blind to. So we need help, or at least I do.
Here's my question to Susan Barry, any optometrists in this group and to anyone else who has crossed the bridge from flatland to binocularity: how does it feel to see in 3D as opposed to 2D? I am not asking what it looks like because that's too abstract for me. People try to describe depth to me and they might as well be speaking in Greek, I don't understand anything. But I can evoke feelings. I am not talking about the feelings of surprise at the steering wheel popping out or the cherry tomato in the lunch salad popping (examples from "Fixing my Gaze"), but what does it feel like to see in 3D?
I want to feel what it's like to see in 3D to help me get there, but my only experience was with 3D glasses looking at a computer screen and seeing the soccer ball come out of the screen. I can't transpose that experience to the real world because it's freaky to imagine everything popping out of where it is and I have no idea how to do that.
Thanks in advance!
This is very true for me as well. For instance, when I'm driving, I try to look with two eyes at the same time; it is useful because I don't need to concentrate on a small detail, but on the whole. However, whenever I need to check one of the mirrors or the speedometer, I can only do it with one eye! When I look back again to the road, I can switch to using both eyes.
Life Savers Exercise!
The 2D-3D language/experience divide has weighed on me quite heavily since I first started in VT. For me, it took a long time for me to feel comfortable identifying things as "looking 3D." As an infantile esotrope with no experience seeing in three dimensions, I felt very torn about the fact that (a) I wanted to see in 3D and (b) I had no idea what such a thing might "look" like. Indeed, my first real notion of how different my visual experience was from others did not occur until I was in my mid-20s and heard Sue Barry talk about her "first" snow on the radio - a story that made me re-evaluate my own experience and re-imagine a new perceptual world.
During my VT sessions, I would occasionally be asked to gauge whether or not something looked 3D, which seemed like a fine question for someone who knew what they were looking for, but left me feeling more than a bit confused, especially when the images I was being queried about included a lot of environmental cues. While in the early months of my VT, I would stare at corners and other straight edges (tree trunks, light posts, anything with a clear edge) and wonder whether I could detect some depth or whether I just wanted to detect depth. This was a big internal struggle, and I found it very difficult to gain any confidence through normal exercises. But I was able to participate in a study for several months that focused very specifically on looking at how adult brains could learn to perceive depth. Although my "improvement" as measured in the study plateaued pretty quickly, my confidence in my ability to detect depth really improved.
Two years ago, I had no binocular vision. Today, my visual system remains, lets call it a work in progress, but I have had some quite remarkable improvements and, for example, can perceive some depth (between 60 and 100 seconds of arc, for those who enjoy numbers). On days like today when my system is feeling quite stable, I love walking under and near trees and perceiving the space occupied by each of the leaves. Finding the words is difficult and plausibly impossible for me because I feel like what I have gained is a sense of that which is not there: the space. I think my latest favorite analogy is this: imagine a glass paperweight with a flower in it. As you roll the paperweight around in your hand you can see all of its sides and get a sense of where each of the petals, leaves, and stems exist in space. There's also probably something to the optics of the sphere that make parts of the flower seem closer than others. In any case, the glass that surrounds the flower draws attention to the gaps between each of the petals, the leaves, the stems. This is, I think, why I love looking at leaves - the leaves may not individually be all that interesting, but the space around and between them is suddenly... there. But not. Because it is, after all, just space.
Speaking of language divides, I think another one that may be just as bewildering for me is the language to describe the experience of looking through my amblyopic-behaving eye (I've been told that because my acuity is so good, I don't technically have amblyopia, but that my weak eye exhibits all the usual features... crowding, etc). With my strong eye open, my weak eye is generally content to follow (or be suppressed, as this is still a bit of a trick for me at times), but when I am relying on my weak eye to see (a) with my strong eye covered or (b) a different image from my strong eye, all sorts of hijinks occur. In particular, I find myself flummoxed on occasions when the left-eye image is not only moving, but unlocatable, as in I would love to describe where it is, but I just can't tell you where it is. Even if it weren't moving, it feels like I might not know. The best I've come up with is that it feels like the right-eye image is stable and the left-eye image is wandering in its own spatial plane, but I can't figure out where that plane is. Has anybody else faced this? Any thoughts?
Anna, I really enjoyed your recent post. I can't relate to the floating amblyopic eye issues you indicate as both my eyes are pretty functional although have different acuities.
The part about seeing space is something Sue writes eloquently about, but, I often doubt whether I'm really seeing the space or just wanting too so badly that I think I am---after all, I haven't seen 3D in 50 yrs, how can I be sure I'm really seeing it now? I find myself pretty sure I'm "getting it" but then I also realize I have to remind myself to pretend I'm in a 3D movie in order to experience what I assume is 3D. I mean, after 50 yrs of 2D, how would I really know if this is really 3D?
I wonder if seeing depth and 3D is more of a spectrum rather than an all-or-none phenomenon...can any optometrist clarify? Thanks
I completely understand what you mean about the trouble of deciphering between perceiving depth and just really wanting to perceive depth. I feel very lucky to have participated in an activity that gave me much more confidence in my ability to do so. Otherwise, I think I would still feel very uncertain about what I was really seeing. I haven't been to a 3D movie in years and my only real recollection of previous 3D movies is that everybody else seemed to be seeing something that I wasn't. Alas.
My understanding is that depth perception very much is a spectrum experience. Let's hope the experts weigh in, but here's my sense of things: The unit that optometrists use for their measurements is seconds of arc, which provides some measure of the distance between two objects required for you to be able to detect that they are in a different plane. "Normal" is 40 seconds of arc and under. Apparently 3D movies usually require about 300 seconds of arc. People with limited depth perception measure around 3000 seconds of arc. There are probably some other measures or metrics, too, and it would certainly be interesting to hear about that.
I'm curious about the difference between the experience of having no recollection of depth -> gaining depth versus losing and regaining depth. I remember "learning distances" so that I could drive and park cars when I was a teenager because the world was flat. Since I've been gaining depth, I've had times where I felt like I had to learn how to interact with space that I had never seen before... although I could detect the space better, I didn't quite understand how I fit in with it at first.
I kind of think of my acquisition of depth perception like the world going from being a picture book to a pop-up book. At first it was a really simple pop-up book - just one layer. As my depth perception improved, two dynamics occurred. The background layers kept moving backwards and more layers started filling in. Sometimes it was really noticeable and exciting, like one day I went outside and suddenly the trees on the opposite side of the street were in a new layer distinct from the buildings they stood in front of. Or one of my most notable changes came when I started being able to detect depth within tree leaves (at first I had tree trunks that stood in their own plane, with the leaves sort of all flat up above, then I got branches, then I got leaves). Even today, I marvel at how the various "layers" of the tree become deeper as I get closer. Super cool.
You are correct, Anna. Stereopsis is definitely on a continuum or spectrum. I blogged about that here. The "seconds of arc" metrics are a reference that we use in the profession, but it is only one aspect of stereoscopic vision. It is literally referred to as stereoacuity, so it has an exact parallel to visual acuity.
Sharpness of sight has little to do with how vivid your stereoscopic experience is. For example, say we give someone a random dot stereo target -- which works like the "Magic Eye" experience -- but they have poor visual perceptual skills in discrimination and/or figure ground. They may not be able to report what they're seeing even though we can measure high degrees of stereo acuity through other forms of testing. That is why "depth perception" isn't synonymous with stereoacuity.
What you are developing is your binocular perceptual abilities, and applying those improved perceptual skills to appreciating a greater sense of two-eyed depth in the real world, which is more important than what you perceive in simulated booklets or entertainment media. I like your emphasis on seeing space within and around natural scenes such as leaves/trees (and as Sue and others have alluded to, negative vs. positive space). That is what differentiates "real reality" from virtual reality.
Though it sounds simplistic, if you think you are just willing yourself to see space, the ultimate test is to cover one eye and see if the space you think has emerged collapses. Sue has made the point that for those of us with "normal" depth, we can't simulate what you see for ourselves when we cover one eye because we have a lifetime of accumulated binocular knowledge that allows us to judge space. But it would seem that it can work for VT patient developing BV to cross check your perception by covering one eye and seeing if the cues you're putting together are indeed two-eye cues.
Thanks Dr. Press for the clarification. Anna K, I totally get it when you say you're not sure if you're seeing something new or if you are just trying to see something anew. My hunch is that we're prone to over-analyzing because we're so caught up in our visual worlds as a result of VT. I figure that if something catches our attention as being different, whether it be a corner or mildew, it is different, to us.
Seeing as how so many of us have become arborophiles (tree lovers), I wonder what would happen if we were doing VT in the desert! Would we be staring at sand and palm trees?