Dr. Kenneth Lane wrote a wonderful book about visual processing issues and how to address them. You can purchase it at Barnes and Nobles for about $50.
The purpose of the book is to offer to parents/teachers some insight into visual processing issues and to offer some tasks you can do at home/school to address these visual issues. IF you are one of my IM parents, check it out on my parent resource shelf in the waiting room. I have incorporated many of the these tasks, plus specific visual processing tasks learned through hours of IM training into my visual processing mode of IM. That does not mean that I am offering visual therapy. No, I am an educator, not a visual therapist. If you want visual therapy, go to a visual therapist. If you want an educator, employing the best she knows about IM and your child's strengths and needs who's goal is to to improve your child's ability to learn through a variety of IM tasks, then check out IM Focused.