Saturday, June 21, 2014

The accommodative rock demonstrated

This is a video of me performing an exercise called 'accommodative rock' or a version thereof. You need a tiny letter chart to hold in your hand and another big letter chart on the wall in front of you. The exercise simply consists of alternately reading a letter from the paper in your hand and then a letter from the chart on the wall.


That sounds pretty easy and straight forward but with a history of strabismus (surgery), it isn't. Both stimuli require very different responses from both they accommodative as vergence systems. It's taken me years to just be able to produce these responses correctly but achieving both states isn't enough. You need to be able to 'rock' back and forth between them in an automatic, fluent motion without losing too much time, juice or concentration! Ideally it should not require one's full attention merely to execute the physical movements. My goal is to be able to do it well and without effort. Have a look at my current level when executing the accommodative rock.




What can we say about this aside from the fact that I need to work on my decorating and directing skills?

I gradually move the handheld paper to the right. Maybe because I get tired, maybe because it's easier to view it that way or both. That compensating behavior has to go.

- Wandering OS. The left eye is my inferior, 'lazier' eye. To remedy this lack of speed and control it could be appropriate to execute this exercise also while patching one eye. This way I strengthen each eye individually as well as the team.
To specifically stimulate my left eye or the brain activity associated with it, I already apply a blurry filter on the right lens of my glasses each morning until I get tired. I prefer 'blurred out' patching over full occlusion because it still allows sunlight to enter both eyes.

- The far away target needs to be on the same height as your face, not up. On this occasion my webcam was blocking the view but normally it'd be straight ahead to stimulate near and far viewing at the same height. The shift to superior gaze is an extra hurdle we want to keep for later.

- Needs to be executed more slowly to solidify skills.

- You can't see this in the video but when looking at the nearby letter chart I get double vision midway of the exercise. In this case the misalignment was vertical. The print is very small and requires very precise eye movements. Halfway I was already tiring and my accuracy was getting sloppy. This kind of motor imperfections will ultimately be eliminated entirely.  I know this because I've seen things improve again and again over the last three and a half years. Refine, refine and more refining.One day I'll simply wake up with a rock solid gaze.

Also watch:
- Instructional video with more information on how to execute the 'accommodative rock'
- You want more evidence? I'll give you some evidence right here!

Also read
- VT and eye movements

3 comments:

  1. You may want to try patching the weaker, lazy eye instead of the stronger eye.

    Here is a link to an article which suggests patching the weaker eye with a diffusser for 2.5 hours could improve binocular skills immediately after the patch was removed.

    http://www.nature.com/srep/2013/130912/srep02638/full/srep02638.html

    I'm very impressed with all the hard work you've put into vision therapy. You're a real inspiration to a fellow strabismic.

    ReplyDelete
  2. Thanks for the compliment, man! Means a lot to know the work is not just useful for myself. :)

    Someone I know read that study you mentioned and said the sample size was very small. This reduces the power of the study to next to nill according to her. But even regardless of that fact it seems very counterintuitive. It's like saying 'You'll get better at something by not doing it'. Haha!

    I've launched the subject in our DIY Vision Therapy FB group and the feedback was nonetheless interesting. It seems that for some patients who experience eccentric fixation and abnormal correspondence inverse occlusion might have a 'resetting' effect. Normal fixation and correspondance are prerequisites for establishing solid binocular vision. I personally don't have eccentric fixation or abnormal correspondance so it's hard for me to relate. Since I have normal correspondance and fixation, I feel like 'classic' occlusion (full or with translucent patch) is the way to go for me in order to get my left eye to participate more fully. Of course, patching alone is not going to do the trick as you know... ;)

    Anyway, I'd like to invite you to our group (https://www.facebook.com/groups/diyvisiontherapy/). I think you will enjoy it and learn a lot. Cheers!

    ReplyDelete
  3. Your Blog is Really Nice. you have sharing the Really Good Information.
    Dr Madhu Karna
    Eye Specialist in India.

    ReplyDelete