Because the VEP is an objective test of the visual system, it can be used to test patients who claim they cannot see but have no obvious pathology. A normal VEP, especially at small check sizes, is an indication that the optic pathways are functioning normally, at least to the level of the primary visual cortex. You should watch suspected malingerers carefully to make sure that they do not close their eyes or avert their gaze from the test pattern during the recording process.