The test is performed by attaching leads to the skin at each side of each eye. It provides valuable insights into the function of the retinal pigment epithelium (RPE) and is particularly useful in diagnosing various retinal disorders. EOG relies. This kind of recording is an electrooculogram or EOG. An EOG records eye movement because of a voltage difference between the cornea and the retina (Figure 1). The technique has been used in various fields such as ophthalmology, neurology, and psychology to study eye movements and diagnose eye-related disorders.