@rangerrebewI began to read when I was 3 yrs. old. I entered the first grade and was moved to the third grade. When in that third grade class, Mom and I were in the car, I was in the front seat, and asked this question, "Is that car coming or going?" She took me to the eye doc as soon as possible. I was near sighted and have worn glasses since that time.
If my eyes didn't track together like this article says, I don't think I would have been able to read or coming up with the word would be a real task for just one word.
I hope parents are smart enough to recognize their kid isn't reading when they should read and go to the doc to find out what is wrong, like my Mom did even though I was reading.