Thursday, January 19, 2012

Vision: I'm Coming Around the Bend

Was a bit late to my last vision therapy appointment, unfortunately.  Did back to back doctors' appointments and my day's schedule slipped.  So, I didn't do as much as what I wanted which was unfortunate.

When I walked in,  I had skipped lunch and was as hungry as all get out.  I remarked to Becky that if she had any children who were misbehaving that I would be glad to take them off her hands and eat them up.  She said that she could have used me on Monday.  Lucy, our receptionist, ran off and very kindly rustled up some soup and salad out of the office kitchen.  I was ever so grateful.

Visual System
Image via Wikipedia
I was working with Becky, the head therapist, and I always do get a lot out of working with her so I hated cutting short my time.   She did a quick rough check of my vertical alignment with some prisms and found out that I only needed two diopters base up.  This is great news as I read that correcting vertical alignment with vision therapy and a prescription for prism lenses can be done up to eight diopters.

So, what's a diopter?  According to Wikipedia, a diopter is a "unit of measurement of the optical power of a lens or curved mirror, which is equal to the reciprocal of the focal length measured in metres (that is, 1/metres)."

Well, diopters differ depending on what you are measuring.  You have diopters when measuring a regular prescription and you have diopters when measuring the correction for a prism.  In my case,  for two diopters that means I am misaligning my world vertically by 2 centimeters when looking at something one meter away.  Apparently, I have been compensating for this by tilting my head slightly and cocking my body askew.  Wearing prisms will hopefully help correct my posture as I won't need to twist my head around to keep a coherent view of the world.

Back to vision therapy.  I worked on looking at a stereogram and trying to line up dots on 10 white crosses that were arranged along a railroad track.  There's another drill where I used two sticks to point to two different images as I tried to fuse them.  I  also did a visual memory drill where I memorized a picture and answered questions about it while I worked with two sets of flippers.  

Then, I ran off to another eye doctor to get my new set of glasses.  GPS isn't always the most clever device in the world and so I was running a bit late again.   He basically confirmed what Becky saw and gave me a prescription for 1.5 diopter base up prisms.   Base up prisms are thicker on the bottom and thinner on top.   I am also getting transitions lens.  I have always been sensitive to harsh sunlight and glare.  All my life,  I have not been terribly comfortable in bright light and I have just endured.  Apparently, with strabismus, you are just more sensitive to light.  The word strabismus comes from the Latin word, "strabismos" which means to squint and squint I do in bright light.

Adding prisms isn't expensive, only $10 with my vision insurance.   Adding transitions is going to be more expensive.  But, I will get a cute pair of purple prism glasses in two weeks.  Looking forward to my new world.

I really do think I have just come around a bend with my vision therapy and the end is in sight.  I believe that correcting 1.5 diopters vertical is doable.  I really don't think I will need surgery for this.  I think we are going to be hitting the core issues of waking up my left eye and aligning my eyes vertically.  Using prisms with vision therapy to reduce vertical misalignment can be done up to 8 diopters.  So, I think I can do 1.5 diopters prisms and work on slowly decreasing the use of prism as my  eyes get aligned.

It is a big relief to hear some good news like this.

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