A recording of voltage changes resulting from shifts in position of the eyeball-possible because each globe is a positive (anterior) and negative (posterior) dipole; along with the EEG and the EMG, one of the three basic variables used to score sleep stages and waking. Sleep recording in humans utilizes surface electrodes placed near the eyes to record the movement (incidence, direction, and velocity) of the eyeballs. Rapid eye movements in sleep indicate a certain stage of sleep (REM sleep).

a record of the electric currents that result from changes in standing potential between the front and back of the eyeball as the eyes move

also called an EOG; the detection and recording of eye movements, essential for determining the different sleep stages.