Our VT also had nothing to do with acuity - our dd actually had 20/20 vision the first time she went through VT. Our experience with VT has been that it's all about how the eyes work *together* (acuity refers to how well each eye can see at distance independently). Our dd had 20/20 acuity, but her eye muscles were very weak which resulted in severe double vision, her brain essentially turning off the vision in one eye much of the time, very limited peripheral vision, and her eyes did not track together while reading or following objects. The way the therapists judged progress was by discrete goals that went with each type of exercise. For example, one of the exercises that helped with convergence had her scan a page looking for a specific pattern of letters which she had to read out loud; another had her point to numbers that were scattered about a page in order. She was timed and had goals to decrease the time it took; once she reached a specific set of goals she was done with that exercise. The therapists also measured her peripheral vision periodically and you could track progress that way, and we could also things change, most specifically her reading ability sky-rocketed after around the third month, and she also stopped holding her head at odd angles while she was reading or doing homework. She also stopped accidentally bumping into things and falling over her own feet as well as she stopped dropping crumbs everywhere at the dinner table
FWIW, her vision eventually got worse (acuity) and her double vision came back. She wears glasses now to correct for the acuity challenge, and is going through vision therapy again - but the goal of vision therapy is still entirely unrelated to acuity - we don't expect it to improve with VT at all.
Best wishes,
polarbear
