I couldn't understand either but JAR-FCL 3 does state that a person with "significant defects of binocular vision" cannot be certified, and an esotropia will affect binocular vision, and in my case stereopsis etc etc. While both eyes are healthy and my near vision and distance vision are fine (albeit with some correction which is within limits), the two eyes don't work together so there's a problem with fusing the image from the two eyes so I see the world in 2D (by the textbook, in reality apparently my brain has developed other ways to perceive depth but I still can't do those optical illusion things etc).
I'm hoping that if I have corrective surgery again to align the eyes and it's succesful, the fusion will develop and I'll have normal stereo-vision.