I have been relying thus far on a couple of doctors (neuro-ophtalomo and OD) to examine my convergence. Each use their own method. Both see major convergence deficit/ high level of CI.

Recently I saw a neuro-ophtalmologist who came to the conclusion that I do not have much CI. She did this with two tests. One that is quite new to me: she asks me to look at an object that is far and she passes something in front of each eye very rapidly and examine my eye movement. She said she does not see an issue. I asked her whether she would be willing to use the prism ruler.

I am not sure how many of you are familiar with the prism measurement. Usually, the way I understood it, they test how high up you can go on prisms (diopters) before the image becomes blurry and then doubles. The higher the value the better is the convergence (the smaller is the CI).

So far, with my original doctor, he finds out that very soon I start to double, meaning my reading is very low, consistent with bad convergence.

The new doctor instead interpreted the fact that the image doubles so quick, at 2-3 diopters!, to mean that I do NOT have CI because, the fact I cannot handle a prism means I do not need a prism.

Everything I read so far (and I am very limited in my ability to read) suggests that whatever she was doing is in contradiction with not only what my doctor does but also with the textbook. Some videos are available online.

Both doctors are in top hospitals in the US. My doctor is more senior while the new doctor is a new assistant prof. But I cannot imagine any doctor making mistakes about CI readings...

Any thoughts?