Thursday, August 22, 2013

#75 session

Things are going well.  The light tube is about where it was yesterday.  It's still a glowing green circle, although I did notice some changes--I think I'm starting to see the beginning of fusion.  It's hard to explain how it's different, except, it looks more detailed, and summed up from both images.  And also, the accommodation difference between each eye is lessening.

Tetris went well.  I've been trying to do about 1.5 hours, but today I feel like I hit a brick wall around 1.25 hours, so I just stopped at that point.  I don't think I talked much about the cyclodeviation that I have--only that it's a great source of anxiety for me, because I have no idea how there could be an exercise which untwists the eye.  My vision therapist from a while back said that cyclodeviation is usually caused by surgery, which very likely is true in my case, since I have had around three surgeries before I was five years old.

I noticed it around six months after I started doing vision therapy with my optometrist when I started noticing the input coming in from my lazy eye.  I noticed that there was a twist in the visual input that came in from the lazy eye when I was looking at objects that had straight lines, such as license plates.  She had me do Bielschowsky after-image tests which showed some anomalous correspondence, but in addition to that, it revealed that the lines forming the crosshair were not even perpendicular, but slightly off kilter.  So she had me do some other test designed specifically for cyclodeviation, which corroborated what we suspected.  When I asked her why she didn't test for cyclodeviation along with anomalous correspondence when we did the evaluation in the beginning of vision therapy she was visibly embarrassed and I think she might have even said 'whoops.'  It's only my money I guess.

I imagine that it could be fixed with surgery by a master surgeon, but that's sort of a weird way to look at it considering surgery is what caused the cyclodeviation to begin with.  In my mind what I think might be going on is that the superior or inferior oblique muscles became uncalibrated.

So you've got three sets of muscles in the eye: superior and inferior oblique muscles; superior and inferior rectus muscles; and lateral and medial rectus muscles.  If you look at the drawing, only the superior and inferior obliques latch onto the eye from the side, where the muscle passes through a pulley system.  If you look at the action that those muscles would have on the eye, it looks like torsion, like it would cause the eye to twist.  So something like that might be going on... like those muscles are messed up.

My hope is that when my lazy eye is fully powered up that my brain will do some compensation--it will untwist the image in software, sort of like how the brain compensates for a bunch of different things, such as missing information.  I know that if you wear upside down glasses, which flip the view of the world upside down, after a few weeks of headaches the brain will flip the image back rightside up.  Then when you take the glasses off again, the world will again be upside down, then again, after a few weeks of headaches it'll re-flip the world rightside up.  The brain is involved to an amazing degree when it comes to what you see.  Hopefully it can accommodate for a little torsion.

Anyway, when I play Special Tetris, I can notice this cyclodeviation pretty obviously.  On the lazy eye there's a counterclockwise twist.  I'm just going to run the experiment and make the lazy eye less and less lazy and then I'll report what happens.  Will I fuse and have the super image be somewhat weird because one of the fused images is twisted?  Will I be able to fuse at all?  Or perhaps the brain will compensate, making the apparent cyclodeviation completely unnoticeable.  We're going to find out.

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