New clinical test of retinal function based upon the standing potential of the eye

(1) A description is given of the changes which occur in the standing potential of the eye when retinal illumination is altered. (2) Electrophysiological experiments which have permitted the identification of the site of origin of the potential, and have analysed the mechanisms which are related to the alteration in potential, are briefly reviewed. (3) A clinical test elaborated from these experiments is described in detail. (4) The test has been employed in the investigation of many retinal diseases, and abnormalities have been found. (5) An attempt is made to assess the value of the new test and to relate it to other clinical electrophysiological findings.