Maculopathy and neuropathies are included in the long list of diseases of the visual pathway that permanently impair visual function. As there are considerable evidences related to the nature and evaluation of maculopathy and glaucomatous neuropathy, objective and reliable techniques are needed for visual function evaluation. By using PERG recordings, doctors are able to differentiate between normal subjects and subjects with ocular hypertension notwithstanding a normal optic disc and VF. PERG can provide important diagnostic information regarding the functional integrity of the macula and ganglion cells.