Electrophysiology of eye and visual pathway is useful tool in ophthalmology and neurology. It covers a few examinations to find out if defect of vision is peripheral or central. Visual evoked potentials (VEP) are most frequently used in neurology and neuroophthalmology. VEP are evoked by flash or pattern stimulations. The combination of these both examinations gives more information about the visual pathway. It is very important to remember that VEP originate in the retina and reflect its function as well. In many cases not only VEP but also electroretinography (ERG) is essential for diagnosis. The seminar presents basic electrophysiological procedures used for diagnosis and follow-up of optic neuropathies and some of central nervous system diseases which affect vision (mostly multiple sclerosis, CNS tumors, stroke, traumas, intracranial hypertension).