Convergence Insufficiency.

I had an educational eye exam last year, and discovered that I have managed to make it to the age of 29 with an undiagnosed eye problem. This all started when my niece's developmental therapist wanted to test the entire extended family for learning disabilities. Among other things, she showed me a picture of a cube like this:

You and I both know that this is a static picture. It's not moving. My brain knows it's not moving. Obviously it's not moving. However, the therapist asked me to count the number of cubes in the third row and then asked if the squares were moving. You know, when I really look at it, the cube moves a bit like this:

The therapist also showed me a blank musical staff and asked if the lines were moving. Intellectually I know they aren't moving, but if I really look they do this:

The eye problem is called a convergence insufficiency. It means one of my eyes points out and up, instead of in perfect alignment with the other eye. Something like 15% of kids have this issue, but it is usually caught and corrected with eye exercises. Convergence insufficiency can make everything look blurry, especially sharply-contrasted things like words on a page, or black and white patterns. It can make it difficult for kids to concentrate, and make reading difficult. I've always been a fast and avid reader, apparently my eyes are really good at compensating. The illusion of everything moving is caused by my wonky eye perpetually trying to align itself to focus and then rapidly flicking back to its natural placement. To correct this I now have prisms in my glasses. My glasses are tinted blue-gray to stop solid colors from looking like magic eye puzzles.

The eye doctor also determined that it takes a full three seconds for me to switch focus between tiny fine print up close and the eye chart on the wall. Now I have blue-tinted prism bifocals and I can see everything far more clearly than I ever have before. It's like the difference between regular and high-definition television.

Sharing these revelations with Z was fun.

Guess who else has prisms now?