Hering's law I (Karl Ewald Konstantin Hering)

States that the corresponding muscles of the two eyes are always equally innervated: common conjugate and vergence commands yoke the movements of the eyes so that one eye is never moved independently of the other. This challenged Hermann von Helmholtz' view that each eye is controlled independently and that binocular vision is learned. Hering won the argument then, but new research has suggested that primates, like chameleon, may program movements of each eye independently.