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

Some are color blind. I am stereo blind.

Archive for December 2011

Staring “off into space” with both eyes

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I caught my eyes at play this morning, while sipping coffee by the fireside in the pre-dawn gloom.

I must have been really staring “off into space” because a light appeared and disappeared. “What??” became my focus, and the light instantly disappeared and I could make out a grocery bag that I had set on the kitchen table. Hmmm-mm.

I closed my dominant left eye (the eye my brain uses in “what?” mode to the exclusion of information from the right). There appeared the light through my half-blind eye— the green clock numbers on my stove! Aha! The bag was blocking the light from the left eye but not the right.

What a happy event, my randomly plopping the bag down and not putting it away last night!

I settled back in my chair and resumed staring “off into space” and enjoyed the flickering green confirmation that both eyes were “on” and working.

Way to go, right eye!

Lynda's diagram

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Cat’s Ear and Coffee Cup

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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]