is that they test acuity, but fail to evaluate convergence, accommodation, tracking and other visual efficiency skills. A child can have 20/20 vision and still have major visual efficiency deficits.
Our opthalmologist told me my dd's vision with eyeglasses was more than adequate for reading (20/30) and that her difficulty learning to read had nothing to do with her eyes. He was wrong. When I took her to a developmental optometrist for evaluation, she was able to show me how my dd's eyes failed to function normally in a variety of ways.
Vision wasn't the only problem my dd had with reading. She also had severe phonemic awareness delays and needed a structured, multi-sensory reading program. However, had we not addressed both of her areas of deficit -- phonemic awareness and vision -- she would not have been able to achieve fluent reading of text. Actually, even these two therapies were not enough. Because she had lived with severe visual efficiency deficits for so long, she also needed cognitive skills training to develop a variety of skills that lagged because of the continuous sensory deprivation she had experienced.
Not all children with reading problems have a visual efficiency issue, but many do. At age 8, my dd was able to read individual words at a 2nd and 3rd grade level -- given unlimited time. She was extremely disfluent when reading text, however, even at a 2nd grade level. She skipped words, skipped entire lines without realizing it, ignored punctuation, substituted words, and would have to sound out the same word over and over again even in the same sentence (no short-term visual memory for the words). After vision therapy and cognitive skills training, with no additional reading instruction, she was able to read the first Harry Potter book out loud fluently. Her visual efficiency and visual processing deficits were interfering with her ability to apply what she knew about phonics.