The hand is quicker than the eye

And more accurate, too. A researcher at the Ben-Gurion University of the Negev has found that fingers correctly anticipate the length of a line, even when presented as an illusion that misleads the brain. Their is a hypothesis that the brain actually has two parallel visual systems, one for perception and one for coordinating movement and action.

However it arises, I'm not all that surprised at the result of the study. I have noted that, when playing the piano, I usually play more accurately when I can anticipate the feel of the chord I am about to play, imagining the position of the hand and fingers before they actually hit the keys. Looking at the keyboard is much less helpful, except when first learning unusual passages.