Difficulties while reading, working, and learning to play the cello caused this adult patient to seek a comprehensive vision exam with a developmental optometrist found with COVD’s Locate a Doctor tool. After a diagnosis of convergence insufficiency, he was prescribed glasses with prisms and a course of vision therapy. Follow his journey below as he retrains his brain and eyes to work together.
Weekly vision therapy and morning at-home sessions continue to keep me thinking about my vision a lot, and I came into the office this week with a pretty big speculation. Something from my childhood had always seemed a bit strange–my parents had elected for me to repeat preschool, telling me later in life that it was because I “got lazy.” Being the first-born child, this never made sense to me: my answer to “jump” had always been to ask how high. So why would I refuse to do my schoolwork?
Now that I’m finding out that my brain has learned to ignore my right eye to prevent double vision, I’m thinking that maybe my child self didn’t want to write everyone’s name on Valentine’s Day cards because I was miserable trying to look at them.
My fifth vision therapy session was definitely something different. The new activitylast week–looking through large, strong lenses and trying to make the blurry image clear–had raised some questions for my vision therapist. We had both been surprised to find that looking through a -3.00 lens and focusing intensely to bring things to clarity gave me the best image I’d had yet, even better than with my prism lenses. All the weird, indescribable after-images I see around text seemed to be scrunched in on themselves and united into individual, clear letters. My vision therapist told me she’d have to get back to me on this one as she wasn’t quite sure of the reason why.
The answer at this session came in the form of a fascinating activity called the Macular Integrity Test (MIT). In a darkened room, I was asked to sit in front of a small box-like device with letters and circles in it and another box-like thing behind it, glowing bluish-purple and making a noise I can only describe as “like an old-timey movie projector.” My vision therapist stood in front of all this stuff and looked down at the top of it, and I couldn’t help but laugh because the strange device made her look like she was about to tell me a ghost story. It was kind of spooky!
I was asked if I could see a moving shadowy area, called “the brush,” which I could: it was kind of a flickering airplane propeller-looking thing that moved as I looked around the blue area. My vision therapist asked me to try to move the brush to line it up with various letters and parts of the circles, using my better left eye first. It reminded me of trying to look at the after-images you sometimes see after looking at a bright light and closing your eyes. Just like those after-images, it would always run away from me when I tried to look at it, scooting up and up and up. But I figured out that looking at the bottom left of the letter would aim the brush at the center of it.
When we switched to the right eye, it turned out that the technique didn’t quite translate and I needed to look at the lower right of the letter to aim the brush properly. But having figured it out on the left side made me get the right much faster. We were done in a few moments and I was eager to hear what it all meant.
Apparently, the brush shows where the center of my visual field is, and normally it would line up with the letters automatically because that’s supposed to be what I’m looking with. But the fact that I was looking away from the letters’ centers means I do something called eccentric fixation and am using an off-center part of my retina to see. How on earth did that happen? Probably another way I compensated for thedouble vision created by my eyes not coming close enough together. But just like last week, this interesting finding also led to another question: what does it mean that, to line up the brush and letters, I had to look down-left with my left eye and down-right with the right one? Also just like last week, I’ll have to wait to find out.