THE CORNEO-RETINAL POTENTIAL DIFFERENCE AS THE BASIS OF THE GALVANOMETRIC METHOD OF RECORDING EYE MOVEMENTS

Abstract

That the galvanometric method of recording eye movements recently reported by Meyers and by Jacobson is based, not upon the summation of action currents from the extrinsic ocular muscles as these writers believed, but upon a persistent corneo-retinal potential difference, presumably arising from the high metabolism of the retina and the (relatively) low metabolism of the cornea, is indicated by the following facts: (1) The observed polarity of the galvanometric effects associated with eye movements fulfills the expectations arising from the corneo-retinal potential difference hypothesis and not those from the action-current hypothesis; (2) passive movements of the eyes produce galvanometric deflections strictly comparable in magnitude and polarity to those produced by active, voluntary eye movements; (3) passive movements of the eyes are accompanied by virtually no galvanometric effect after the retina is destroyed by chemical means; (4) the existence of a corneo-retinal potential difference has been directly demonstrated by earlier investigators as well as by the present observations.