I agree about finding him a developmental opthalmologist. We've just been this route and, with similar symptoms, the diagnosis was to "wait and see." Apparently, in Dd's case (she's 9yo), Vision Therapy wasn't recommended as for her it's not a focusing problem (I don't mean "correctable," but visual focusing), but a neurological one.
Maybe his cognitive development is beyond his physical abilities needed to read and write?
And, yep, that's what they said about Dd, too! Except, in our case, the spread is different. Handwriting at about a 3rd grade level (she would be 4th), reading comprehension generally high school, word decoding nearly adult level, and physical reading ability about 3rd grade.
I think, however, that there are many, many factors involved in eye development. We've been told to bring Dd back in the future for re-assessment, but otherwise, to just continue what we're doing - and focus on keyboarding to compensate for her handwriting issues....
