Wide-eyed Wonder: an artist's musings on three-dimensional vision

Some are color blind. I am stereo blind.

Archive for the ‘peripheral vision’ Category

Dance of the Red and Green

with one comment

I was inspired today to open my desk drawer of vision therapy tools and dust off my red-green anaglyph glasses. Why? Because NOVA recently featured Sue Barry in their “Secret Lives of Scientists” program, and put out this wonderful teaser of Sue on her trampoline, grinning and staring at a Marsden Ball with her anaglyph glasses as “Clue #1: A Trampoline, a Ball and Hipster Glasses?!”

Image

Oi! Those glasses have been put away for about a year. I recall the craziness of what I saw through them after losing the vision in half my right retina as almost unbearable, but that was when my vision loss was still fresh. I drove myself crazy with them, trying to get confirmation of some fusion in the lower half of my vision in what Dr. Leonard Press referred to as luster: a luminescent glow of combined red and green as seen by both eyes.

But instead of trying to “get luster,” today I am simply wearing them for a few hours and seeing what happens. Dr. Barry has inspired my curiosity!

My strabby friend Sally is also partly responsible for the inspiration to dust off and try again. She also took a hiatus and discovered vision therapy works, and blogged about it. So I got brave and put on the glasses.

As I suspected, when I really want to focus on, examine and “see” something, the thing is solid green. This is because the central vision in my “red” right eye was compromised by the BRAO. So, while eating lunch, my lunch went green when I scraped my bowl for the last bits of Indian food. Reading also was solid green to the right of and including each word I was reading.

I also expect and do see red on the extreme right, where I still have retina and peripheral vision in my right eye that my left eye does not see (because it is blocked by the bridge of my nose)

However I am surprised by the amount of red dancing around, just to the left of where I am writing and all underneath. It comes and goes in split seconds, but it is there, like a dancing sunbeam.

This is more red than I expected. I’ve been pretty certain my left eye was thoroughly suppressing my half-blind right eye ALL the time, because I see no indication of my right eye’s blind condition. I expected a solid-green confirmation of my half blind eye’s total non-use. Instead, I am using both eyes constantly!

This explains the very rare and thrilling experiences of magic that just “happen” on occasion. If sheer thrill could be made empirical, I would bet my bottom dollar the magic is stereo vision. At some point, I will devote an entry to my “sightings” which I record on my iPhone just after each happens.

Image

My most recently “sighting” occurred after finishing a plein air painting session during Paint Oglebay. I worked a solid three hours trying to catch and record a sunlit path in watercolor. As I hauled myself and my gear back up the trail, I felt brain-drained but happy, and said to myself about my empty-headedness “This is when I see stereo.” Instantly, the leaves under my feet appeared cupped. I stopped and enjoyed a hundred little leaf sculptures that were more real than I could imagine. I didn’t need or want to touch them, just look at them in this new reality. Then, slowly, I resumed walking. The movement of the delicate weeds on either side of the path appeared fairy-like. I became completely immersed and enchanted by the world under my feet with sculpted leaves and waving fronds … all moving in what Dr. Sue Barry calls “palpable space.” How can things feel so grounded and yet moving? It was like the best sort of movie depicting a fantasy world with tangible magic in the air. Unforgettable!

Shortly after this experience, I made an appointment for an eye exam with my Developmental Optometrist who had given me 6 months of vision therapy in 2010-11. I haven’t had my eyes examined since the BRAO occurred 18 months ago for reasons mostly financial and partly emotional. I’m now committed to biting the bullet!

I hope to determine whether some vertical prism in the right lens will help my right eye to see more, and improve my chances of gaining some stereo in my central vision. My optometrist had used vertical prism in my first appointment just after the BRAO, and my ability to focus on the Brock string was dramatically improved. Time to find out if an investment is in the cards.

I do have at least one cheerleader: that grinning scientist with a secret who encouraged me in a May 10, 2011 comment on my BRAO post on the Vision Therapy social network Sovoto:

Dear Lynda – brave lady,

    I’m sorry the retinal specialist had such bad news, but the brain can do amazing things.  With vision, we take current sensory input and combine it with past experience and expectation so, while part of the retina may be dead, how the brain will re-interpret your remaining visual input is an open question.  You may see better than the dead tissue would suggest…  If you learn to see in 3D in the lower half of your visual field, perhaps the brain will “fill in” that information to some extent in the upper half.  In other words, you’ll have a richer view of the upper visual field than predicted.  With your resilience and powers of observation, things could be better than the retinal specialist suggests.

    Best,
    Sue

You can link to all the Secret Life of Scientist clips of Dr. Sue Barry here: http://www.pbs.org/wgbh/nova/secretlife/scientists/susan-barry/

Postscript: at the end of writing this blog post, the dancing red and green have calmed down at times into into a blended red and green that is neither red nor green but lighter, yellower shades of each. Maybe I’m getting some “anti-suppression therapy” happening! One can always hope!

Cat’s Ear and Coffee Cup

leave a comment »

I have commenced to sketch, as best I can, the various scenarios my brain morphs together. Today’s initial sketch for “The Physiological Diplopia Series” is called “Cat’s Ear and Coffee Cup”

One thing that has become of my leaving-flatland-goal + BRAO is Wonderland. Thanks to the three months of Vision Therapy I did have, plus lots of vision research and blogging, I am familiar with aspects of vision that I previously ignored: expanded peripheral vision, heightened motion parallax and physiological diplopia.

Of these three beautiful vision aspects, physiological diplopia is confirmation that my BRAO is not preventing both eyes from working together to look at the same thing at the same time in the same space. In my case, I experience it most 3-13″ or so from my nose, the same distance I was able to create diplopia with the Brock String before my BRAO.

Here is a diagram of this morning’s scenario. Instead of a bead on a string, I was staring at the tip of my cat’s ear just through the handle of my coffee cup which I was holding next to my face about 1:00 from the tip of my nose.

 

111206cat-cup-diag

Next to the diagram is my sketch of what I saw from each eyes and both eyes combined into a brain morph of right and left aspects:

 

The vertical hatching above the right eye cup is my BRAO. Note, when I am using both eyes, I cannot experience physiological diplopia where I have no right-eye vision (this is also true for stereo vision). In this case, in my 3rd sketch of both eyes looking, the top of the cup assumed the left-eye aspect.

The Wonderland experience was seeing my coffee securely held by an open shell spiral that my brain created when both eyes pointed at the tip of my cat’s ear! If I attempted to study the mirage too closely, it vaporized and the scene defaulted to the left-eye image. This is because my left eye has the superior central vision and therefore bears the “what” function of my vision.

I don’t see the brain morph most of the time. Normal people with stereo vision also do not see physiological diplopia unless they allow themselves to, by turning off their own brain suppression. I can’t vouch for how that happens; ask a Developmental Vision Therapist!

* “In an alternating esotropia the patient is able to alternate fixation between their right and left eye so that at one moment the right eye fixates and the left eye turns inward, and at the next the left eye fixates and the right turns inward. Where a patient tends to consistently fix with one eye and squint with the other, the eye that squints is likely to develop some amblyopia. Someone whose squint alternates is very unlikely to develop amblyopia because both eyes will receive equal visual stimulation.” [3]

 

Post BRAO Week 7: Settling into a new way of seeing

leave a comment »

I had a rough 6 week appointment, as the retinalogist was incredibly short and curt “You have dead tissue. You can’t do anything about it other than control the medical condition to perhaps prevent future occlusions. See you in 6 months.”

I prefer the medical term, ischemic, which simply means lacking blood supply. “Dead tissue” just sounds too final, like half my retina will now rot away inside my eye! The fact is, my rods and cones underneath the blood-deprived inner retinal layer are doing quite well, actively making abstract patterns which I see when I close my eyes, or in low light. They’ve been doing this since BRAO day 1. Yes, I will paint these patterns some day!

The swelling has gone down slightly and yielded a hair more central vision. But what a difference a hair more central vision can make— I can now see two eyes when I look at someone with just the affected eye, instead of a person’s right eye only. I expect another hair’s worth of gain and am hoping to be able to read with the affected eye in another six weeks. I can already read huge type fairly quickly, but nothing close to 20/20 on the eye chart.

What my brain can do with that hair of gain has been pretty cool. I mentioned before that my brain is patching together a complete visual field. In the last few weeks, the wrinkled area where my right vision ends and the left begins to fill in is smoothing out. When riding down the highway, guardrails are no longer disproportional and incomplete.

I routinely test for eye-teaming by covering and uncovering each eye while looking at an object to see if both eyes remain fixed on it, and by holding a finger close to my nose while looking at the object to see if the one finger becomes two. Almost always, I pass my test when I consciously make the effort to use both eyes, or when I simply think binocularity may be “happening”.

Inside the chicken coop, this poison ivy was easier to find!

I have been surprised to discover my eyes teaming on their own without conscious effort: first when I was trying to take a splinter out of my hand, then when I was cutting the grass with a riding mower and lastly when I was seeking and destroying poison ivy with weed-killer.

All three vision demanding activities are the result of my new diversion from vision therapy: the 5 acre homestead my husband and I bought in April that we are restoring this spring and summer, with the goal to move in and make it home by fall. Even if I had not had a branch retinal artery occlusion, I would have been taking a hiatus from vision therapy to work on this house and acreage. And, once we move, it will be almost an hour’s drive each way to resume therapy sessions.

Immersion in visually demanding situations where “where” is more important than “what” has been a goal of mine all along: break away from the newspaper and laptop and get out in the wide world and SEE. Frederick Brock states

An individual habitually maintaining strabismic posture may, for certain heightened perceptual demands, use binocular posture if the latter is necessary for the successful of the task.1

Finding “where” I left off cutting the grass to successfully guide myself on the riding mower to cut the next swath required “heightened perceptual demands.” Seeking and destroying the shiny and slightly bronzed three-leaved poison ivy amidst the rest of the grasses and weeds and bushes was also an intensively “where” oriented exercise, and using my vision to guide the stream of weed-killer even moreso.

My new quiet spot ...

Yesterday, one week after the retinalogist pronounced my tissue “dead,” I remarked to Patrick, as we were out for a drive in search of building materials “Wow, those trees seem really close to the road— they’re so tall!” I was surprised when Patrick said “They ARE close!” and suggested I was seeing them in 3D. I’m not certain, but they certainly were making an impact on me. I was feeling somewhat enveloped by their overhanging branches as we whizzed down the highway … wondering if they could fall over on the road on a windy day.

It was a good feeling.

1 Frederick W. Brock, “Lecture Notes on Strabismus” p6

My diagnostic impasse

with 4 comments

"Bottom of Imperfect Impass" creative property of climber Gabriel Deal

Alternating esotropics are the most difficult to treat. (Period.)

My vision therapist stated this twice during my second eye exam with what sounded like a touch of resignation.

This is because 1. we have clear vision out of each eye and 2. the more established our system of alternation is, the more difficult it is to work against it.

My vision therapist contacted two colleagues this week and conducted further testing during my third office visit today. After the testing, she told me that degree of alternating esotropia I have is best not to treat, according to her own instincts and best practices, and the advice of her colleagues.

Apparently, the danger is that I could see double, with no guarantee of breaking through the double vision to gain stereoscopic vision. This is the same reasoning I received during my only other vision therapy eye exam back in 1981.

I certainly respect her professionalism and unwillingness to risk the creation of dyplopia. The Hyppocratic Oath to “cause no harm” is an ideal I desire in any medical professional who tries to help me.

And I deeply appreciate the extra care she has taken to confirm my diagnosis. She has gone the extra mile because this is my second time around, with 30 years of wishing for a binocular solution in between.

She also offered to contact Sue Barry’s vision therapist on the chance that there may exist some crack in the impasse my particular diagnosis presents. However, I am not terribly hopeful for an answer in that direction, as Sue Barry went into her vision therapy with several other vision problems that I do not have.

The malware that my brain has created “fixed” these other problems so that I can read without experiencing eye problems, other than fatigue. I also drive without fear, but this could be mere bull-headedness on my part!

Perhaps another vision therapist would consider taking the risk of giving me binocular fusion exercises, but before I make that decision, I will need to better understand the kind of dyplopia or double vision I might get stuck with, and what clinical evidence or case studies back up this belief.

In the mean time, I intend to further define and publish information about my particular kind of stereoblindness and my methods of coping with it, for the benefit of others. Over 30 years of burying my stereoblindess and hiding it from others has helped no one.

I will also seek out everything my vision therapist can in good conscience offer to improve my vision in spite of the malware, especially so that I can drive more safely and teach art classes and communicate more effectively. What I emailed last week still holds true:

“Beyond pursuing fusion, I would love for you to expound on the connection between peripheral vision and gross motor movements. I am also all for building as much peripheral awareness as I can.

Are there ways to encourage better peripheral eye teaming? Optic flow has been a huge clue, for example.

My goal is to immerse myself in better seeing, with whatever tools I can get and use between office visits!”

And stereoscopic, 3D, binocular vision will remain at the top of my bucket list!

Written by Lynda Rimke

December 21, 2010 at 6:06 pm

Childlike wonder

leave a comment »

“’Curiouser and curiouser!’ Cried Alice (she was so much surprised, that for the moment she quite forgot how to speak good English).”

The first time I got my eyes to see something new, I literally inhaled “HUH?!” in shock and … fear! Then thought, “Oh dear! I have just rewarded my accomplishment with negative brain chemicals. Quick— think happy, Lynda!”

Susan Barry writes in her Psychology Today blog, “Eyes on the Brain”

Novel and rewarding experiences not only encourage people to work harder at their therapy but also have direct effects on brain wiring. When a person experiences something new and gratifying, neurons in the brainstem and basal forebrain are activated and liberate powerful neuromodulators onto circuits in the cerebral cortex. These neuromodulators, including dopamine, serotonin, and acetylcholine, trigger the changes in neuronal connections that underlie new perceptual experiences and learning.

Alice has become a role model, although I never liked her adventures as a child. To be honest, I was mostly terrified by the thought of growing too big and getting wedged in a house!

Alice in Rabbit's house

And I never wanted to be a giraffe. But Alice simply and cheerily says “Goodbye feet!” as her neck grows up and away, because she is enjoying how everything is “Curiouser and curiouser!”

Bring on the childlike wonder! Bring on the dopamine!

Now that I have worn the center-occluded glasses for a week, I take in the whole world with heightened peripheral awareness. Even without the glasses, going up the stairwell at Summit Artspace now reminds me of a Halo game, with the handrails and walls slipping by and out of view. Driving home reminded me Gran Turismo, as the road signs and guardrails flew by (but at a mere 60mph!).

It’s another novelty, this expanded reality. I have much to be thankful for. I am enjoying these Wonderland moments.

Discovering peripheral vision

leave a comment »

I went home from my first appointment and extensive eye exam on Tuesday with instructions to tape the center 1″ of my glasses and discover my peripheral vision system. I emailed my vision therapist the next day:

You told me to “have fun” with my occluded center vision and heightened peripheral vision. I have to tell you— I’m having a blast!

Seriously, I’ve noticed several amazing things (and it’s only half-way through the first day):

  • I automatically go up and down the stairs without reaching to feel the right wall
  • I saw myself go THROUGH a doorway! I was so thrilled I turned and went a back THROUGH the doorway about 3 more times (and then laughed at the cat staring at me and meowing from the middle of the kitchen floor.)
  • I am more aware of my the muscles working in my feet, ankles and legs, and am walking without looking at my feet, or looking a short distance on the path in front of them.
  • I feel taller … more erect … chin up more.

Fixing My Gaze finally arrived, and I am already half way through it. It turns out that the process of perceiving THROUGH has a name: optic flow. Barry writes

As I continued my vision therapy and became increasingly aware of my peripheral vision, I was able to tap into a phenomenon called optic flow. When you move forward, objects to the side of you appear to move backward. This optic flow is fastest for objects oriented at 90° to your movement, and the closer objects appear to you, the faster they appear to move … Cinematographers and video game designers have figured out how to create illusions of motion on flat screens by simulating optic flow. (p. 84)

Perhaps that’s why, every time I go through a doorway, I can almost hear the hum and “whoosh!” of a surround-sound theater space portal!

I’ve since realized I did learn to rely on peripheral vision in my mid-30s, when I was on a worship dance team (there was grace enough for a girl with two left feet to dance in church). I had to look out of the corners of my eyes because I needed to know where everyone was and what they were doing to stay in sync and to keep in my designated “window” in the choreography.

It just never occurred to me to use it always.

With my peripheral vision, I am able to use both eyes at the same time. Perhaps that’s why my body feels more balanced with the occlusion than without.

I am using these new glasses every chance I get!

center-occluded glasses

My new sno-occluded glasses (The Sno Seal is less visible than tape; and the beeswax won’t mess with the carbon lenses. I used the tape to get a straight line, and applied the wax with a very soft watercolor brush.)