I saw some 3D at my vision therapy appointment! My latest appointment was filled with amazing insights, because I had my appointment in a different office location, filled with all sorts of gadgets and tools. I started off my appointment on a swing….I sat cross-legged on a square platform about a foot off the ground, and my therapist Jeri was spinning me around. The whole world flashed past in the most jagged, stilted, staccato manner, which has to do with my eyes’ nystagmus. Jeri always talks about the relationship between strabsimics and movement, so we explored that a bit today.
Next I did some things on the computer. I wore a pair of horrifically expensive eyeglasses that had a little cord hooked up to the computer. I did a Worth 4-dot test, to explore my suppression: none. Then I did a saccades test, spotting a little arrow that popped all around the screen. Next Jeri had me do some Random-Dot 3D images (similar to the those Magic Eye posters from the 1990s.) They sorta looked like this
(except the Random-Dots I was viewing were red squares.)
I was wearing the crazy glasses and holding a purple controller (looked like a SuperNES controller) and was to press down, if I saw a 3D square popping out, press right, if I saw the square on the right, press up, etc etc.
I never saw a square…but I saw something. SOMETHING! A blob! that was sorta floaty! and I pressed in the direction I thought I saw my floaty blob, and it beeped (correct!) This happened a dozen times. I never saw a square. Once I thought I saw a skull. And I swear I saw a dolphin (and Jeri probably thinks I’m crazy because she says they’re squares.) Dr. Len Press recently blogged about how Random-Dot 3D tests like this can be tricky for strabismics, in a post he wrote entitled Strabby Looks to Break through the 2D Wall:
Our field has gravitated toward Random Dot Stereopsis testing, such as the “E” plates above. If a patient has strabismus and is incapable of bifoveal fixtion, the two test plates are indistinguishable from one another.
I’m guessing that must help explain why I didn’t see a proper 3D square, but 3dish areas. Then the computer spit out some results, that I didn’t quite understand, even though Jeri carefully explained that I was seeing 3D, and that I could see an image 4-something units but then it would ‘break’ at 3 something units diverging…like I said, I didn’t really understand the details. Based on those computer results, Jeri said I am ahead of where she thought I would be.
And then Jeri got excited, and beckoned me over to the sleek Italian vectogram/Quoit machine. I remembered reading about this 3D projector stuff in Sue Barry’s book, as Jeri pulled out two postcard-sized piece of clear plastic, each imprinted with this image:
One of the cards said “left” and the other “right”, and Jeri slid them into this projector thing
that I stared at while wearing polarized lenses. And as the two images slide over each other, I saw: a 3D image. It was exciting! I could see the rope curving in a subtly different way than I had seen the rope’s curve a moment before the two slides slid together.
Next, Jeri slid the cards bit by bit to make the image pop for me, which it did…as I looked at it, the ring became smaller and closer. I saw it floating in space, and Jeri asked, “can you pinch it?”
With reserved glee I reached my hand in front of me to pinch it–I pinched it, in 3D, amazed! so excited!
Next Jeri manipulated the cards so that the ring image would recede. I vaguely remembered this idea from Sue Barry’s book, that a person can see 3D in “front” or “behind”. And then, the ring became noticeably larger, and farther away from me. My gosh–it was happening! 3D 3D 3D!
Jeri said, you’ve achieved SILO: An acronym for small in large out. It refers to the presumed change of the perceived size of a test object that a patient experiences, while maintaining fusion when convergence or divergence is varied. She wrote SILO in my chart and circled it.
Here’s a cool old dude and his therapist, doing what I just did with my therapist:
We played around with Quoit rope circles, and Jeri told me I could fuse 21 units (again, forgive me–not in the strabismus biz here, I’m just a strabismic amblyope) which is apparently super-awesome. I think Jeri was wondering if I was seeing any 3D in real life, so she asked me about in my car: do I see the rear-view mirror popping out? is there space around it?
I said no, and I mentioned hat I will pull my sun visor down like, 1 inch, if the sun is bugging me. I am certain this would drive a person with normal vision crazy (try it! see if you go crazy.) This puts the visor about an inch in front of my eyebrows, and I think for normal people, it would be annoying—but it doesn’t bother me in the slightest.
After hearing that, Jeri got out a pair of über-nerd glasses:
and spun each lens around so I had the thickest part at the top of the frames. I put those weirdos on and the world looked: great! I could see so much floor! there were my feet and the ground! and it felt so comfortable. I practically thought I’d be seeing upside-down from the looks of those giant prisms. But it felt better than normal. Jeri said, “let’s go for a walk!” so we walked around the office, and saw my optometrist (who remembered, off the top of her head, my glasses prescription–”is that odd that I know everyone’s prescriptions?” she mused) and most interestingly, saw the edge of the receptionists’ counter.
It was floating out at me.
oh my gosh–my first ‘real’ 3D experience. And it is hard to describe, but there was a difference when I saw it with the prism glasses compared to when I moved them and looked at it normally. It was the same popping-out-ness that I had seen in the room with the Quoit rope circle. It was the same popping blur I saw on the computer. I kept touching the edge of the counter, probably looking like a total weirdo wearing a pair of über-nerds, but I would guess this isn’t the first time a patient has done something like this at the reception area. Everything else looked normal; only the Formica counter edge was doing it. It was as amazing and exciting and obvious and strange and wonderful and as indescribable as Sue Barry had said.
“We call that ‘float’,” said Jeri, smiling.
It was such a fun therapy appointment today! We ran over our allotted time, we were so excited to explore my 3D skills.
Jeri was looking at my initial exam report to find out what my original stereo vision was when I first came to the clinic two months ago. She couldn’t find it, so she went off to ask the optometrist. Jeri came back holding the Randot Test (a cousin of the Stereo Fly test) and told me I had no stereo vision score because I had had no stereo vision.
Doing the test on the upper left, pictured here, I detected the correct 3D dots and my score says “50 seconds of arc” with that portion of the test. The lower the number, the “better” the 3D vision; normal vision is 20 seconds of arc. (Interestingly, I could barely perceive any 3D-ness with the Random-Dots on the right-hand side of the test.)
All of those patched eye activities have helped me get to this exciting point! I am so grateful to Jeri and my optometrist and her clinic and developmental optometry and Dr. Brock and Dr. Len Press and Sue Barry and everyone’s kind words and encouragement–I needed that to be able to do what I’m doing now!
I am grateful for all of this support because I am standing on a firm yet unhelpful opthalmologic foundation, which effectively taught me I have crippled eyes that require glasses, are strabismic, and uselessly amblyopic. But now I am learning to see! in the developmental opthalmology world that says there is inherent beauty and ability in my human visual system!
Those über-nerd glasses are saying it, too: we can help you! (and you don’t have to wear us for real in public!)