No, the developmental optometrist doesn't just check for what we would traditionally think of as eyesight. It's all the "stuff" that goes along with vision and processing. The sort of "eye bouncing" you're describing is exactly the kind of thing a DO looks for, and is exactly what I was worried about. The kid can name the symbols on an eye chart, but he was refusing to look at words in a book. Well, kids don't read from half a room away, so the eye chart thing didn't tell us much!
I don't think what you're describing is what my DS4 is dealing with exactly, but I think he may have something else along those same lines that's interfering.
So good question!
Oh, and LadybugMom: Thanks! That's so nice. I really appreciate the rooting. I'm rooting right back!