Daniel Reid, The Complete Book of Chinese Health & Healing: Guarding the Three Treasures, 1995, 56
The liver controls the peripheral nervous system, which regulates muscular activity and tension. The inability to relax is often caused by liver dysfunction and imbalance in Wood energy. Liver energy also controls ligaments and tendons, which together with muscles regulate motor activity and determine physical coordination. Liver function is reflected externally in the condition of finger-and toenails and by the eyes and vision. Blurry vision is often a result of liver malfunction rather than an eye problem, and even Western medicine recognizes the symptomatic yellow eyes of liver jaundice.
Through its association with Wood energy, the liver governs growth and development, drives and desires, ambitions and creativity. Obstruction of liver energy can cause intense feelings of frustration, rage, and anger, and these emotions in turn further disrupt liver energy and suppress liver function, in a vicious self-destructive cycle.