Why do I have trouble reading?
“If you struggle with keeping both eyes at the same point on the page, you may be able to read fine if asked to read a single sentence or paragraph but not if asked to read for many minutes. We have no trouble recognizing that a child with a mild limp may be able to walk from one end of the classroom to the other with little difficulty, but we would not expect that same child to be able to run a mile on the school playground as well as a child with a normal gait. Why then don’t we recognize the impact that eye coordination can have on an endurance activity such as reading?”
Allow me to refer you to the complete article written by Susan Barry: http://www.psychologytoday.com/blog/eyes-the-brain/201203/why-do-i-have-trouble-reading.