One aspect of your story that strikes me is your frequent mention of your DD being tired at the end of the day, suggesting you find her noticeably more so than typical? Gifted kids have amazing ability to compensate for learning issues: they create incredible workarounds and can look really effective. But doing so can be exhausting. We all get tired and less competent as the day goes on. However, I have learned to see that if my child seems to have skills in the morning that just aren't there after school, then they probably don't actually *have* that skill, but rather are using some intensive and difficult compensation strategies which are increasingly hard to sustain as the day goes on.

My psych actually says she always prefers to test for learning disabilities in gifted kids at the end of the day, because they're not as good at hiding them.

FWIW, my DD is far-sighted to a similar scale as yours, but got glasses when she was 6 (her eyes were starting to wander when focusing got too difficult). I thought they'd be impossible to keep on her; in fact she hasn't had them off since the day she acquired them. So I assume they make a notable difference for her. She can read without them - she tells me they don't change her focus or look of the text - but they make the text bigger and less tiring to read. She also has convergence insufficiency (and dyslexia). We did vision therapy overlapping with reading remediation. There were huge improvements in reading, and I believe - though can't prove!! - that the VT played a significant part in her increased reading comfort (not to mention rapidly evolving art skills). Certainly, before the VT, if you waved a pencil in figure 8s, or brought it towards her nose, or had her jump her sight from one object to another and back, in every case you could see her eyes jerking inconsistently all over the place and unable to stay focused on an object for more than a moment. This no longer happens, and we have to imagine that being able to move smoothly between words and lines has contributed to her major reading progress.

There's a great summary of the evidence base - such as it is - for visual processing treatments; look at the 3rd last clinical practice guideline listed here, as well as the overview of vision-related learning issues (last item):

http://www.aoa.org/patients-and-public/caring-for-your-vision/clinical-practice-guidelines?sso=y

The combination of reading tons, early, but seeming to tire out quickly is, as you note, the kind of thing you might expect to see when you combine a VCI so high that reading is super-easy, with something that also makes reading unusually laborious, like having to work extra hard to focus, or track smoothly. So, to echo aeh, whether you keep looking for something wrong depends on what you are seeing in real life. With a VCI like your DDs, the question may not be whether there are things she can't do, but rather, are there things you expect her to be able to do easily, but somehow seem harder than they ought to? And do they get increasingly harder as the day goes on and she gets more tired?