The indirect method of recording the corneoretinal potential in man consists of repeating eye movements over the same angle, and measuring the potential difference between the starting position and the final position of the eye. The indirectly measured, corneoretinal potential is sometimes referred to as an electro-oculogram and is clinically used as a diagnostic aid.1-4 Experimental evidence indicates that the corneoretinal potential increases in response to stimulation with light5,6 and returns with a "slow oscillation" nearly to the same level which it had during darkness. One oscillatory period, evoked by a constant and continuous light stimulus, lasts 25 to 30 minutes.7-9 The slow oscillation can be brought into synchrony with repeated light and dark phases of 12.5 minutes' duration each.
An additional short-lasting fluctuation of the corneoretinal potential occurs immediately upon change either from dark to light or from light to dark. This initial transient is mentioned
KOLDER H, BRECHER GA. Fast Oscillations of the Corneoretinal Potential in Man. Arch Ophthalmol. 1966;75(2):232-237. doi:10.1001/archopht.1966.00970050234017