Electroretinography based on the totalregistration of bioelectric potentials of the retina in response to light stimulation. Lightstimuli with different parameters duration, brightness and wavelength form bioelectric potentials from the various layers of the retina and cellular structures. These potentials -  signals - recorded using threeelectrodes: corneal (corneal electrode),indifferent (reference electrode) andcommon (ground electrode). To interpret the results of research and forming an opinionshould be analyzed for the ERG signals,which limit automated thanks to the softwarethat came with the recording equipment.

Terms of stimulation parameters amplifiersand methods of the study are standardizedby the International Society of Clinical Electrophysiology of (International Society for Clinical Electrophysiology of Vision (ISCEV)), which ensures the representativeness of the results. However, there are many factors affecting the quality of the recording ERG signals, and thus, the reliability of the study results of patients with diabetic retinopathy that physician electrophysiologist should consider.