Visual Evoked Potential in Pattern and in Flash. The P-VEP is a test or diagnostic tool that reflects the electrical activity of the brain corresponding to the central visual field. For this test, two types of stimuli are performed: the stimulus with a reversible pattern (P-VEP), which consists of the presentation of an image in the form of a chessboard grid, on a television monitor, and due to changes in Contrast in the shades of gray of the grid determines the function of the central nerve fibers corresponding to the fovea, and stimulation with a flash of white light that allows determining the function of the peripheral nerve fibers around the fovea.

Measurement of Potential Visual Acuity. or sweep visual potential (“sweep VEP”), is obtained by presenting a stimulus in the form of vertical bars in shades of gray that change contrast. Its clinical application is useful for quickly estimating the degree of visual acuity in children and in patients who are unable to perform a conventional visual acuity test, and in malingerers.