In a previous publication innervational aspects of convergence and divergence revealed by electromyography were described (Breinin and Moldaver,1 1955). It was shown that patients with intermittent exotropia experienced active innervation of the lateral rectus on diverging from the near point of convergence and at all times when the nonfixing eye deviated outward. This was true for all fixation distances.
This report concerns additional data on the vergence mechanisms. In the cases of intermittent exotropia cited above, a remarkable finding in all instances was the fact that only the deviating eye showed increased innervation of the lateral rectus. The fixating eye showed no alteration of the innervation of either lateral or medial rectus. At first sight this suggested that the exo deviation was due to a monocular dissociation and that Hering's Law was invalid for this condition. If this were so, we should have to speak of an "abduction" rather
BREININ GM. The Nature of Vergence Revealed by Electromyography. AMA Arch Ophthalmol. 1955;54(3):407-409. doi:10.1001/archopht.1955.00930020413012