I saw a TLC special on the unconscious mind. It was quite interesting and relevant to photoreading. They were demonstrating how a legally blind man could still tell which direction a bar flashed across a television screen. They said that this was possible because not only is there a nerve that connects the conscious mind to the eye but there is one that connects directly to the unconscious mind as well. The conscious nerve was malfunctioning in the mans brain but the other one was working fine.

Seems to be quite similar to how photoreading works to me. I know the book natural brilliance also gives an example like this as well.