Now, in western and hindu tradition there's the classical right-hand vs left hand, the former usually associated with light and faith and the latter with darkness and personal henosis. When not outright called "good" and "evil", that is.
However, in taoism the left hand is associated with yang, the principle of light, and in Japanese mythology the sun goddess came from the left eye, while her brother came from the right. This can't be mere coincidence, but I haven't found a lot connecting the two.
As a whole I feel that diving the hands/eyes is ridiculous, but how do you reconcile that?