Being able to move our muscles in a coordinated fluid action is the goal, and proprioceptive feed-back from our muscles is critical, it is rightly called "the 6th sense". As good as the proprioception is however, it does need frequent re-calibration so that we know exactly where our muscles have moved us to - it is Vision that keeps the precision up to date.
The acuity of visual feedback is far more precise than proprioception, allowing the exact and delicately balanced movements of muscles critical to learning, the muscles of the eyes and the hands; just watch the intensity of gaze by a violinist upon their fingers - despite their years of practice!
