The Visually Evoked Potential (VEP)
    VEPs are the electrical response of the brain to a visual stimulus. To
    measure the response, three electrodes are placed on the scalp held
    on by a soft cream.
    Typically VEPs are recorded to a flashing strobe light, reversing and
    appearance black and white checkerboards.

    The pattern VEP is dominated by activity from the central 5 degrees,
    predominantly lower field. This macula predominance means that
    pattern VEPs in children can be used as an index of macula pathway

    Monocular stimulation with a trans-occipital array of electrodes, and
    where possible half field stimulation, can discriminate optic nerve,
    chiasmal and hemisphere anomalies.

Visual Evoked potentials
The Electrophysiology Clinic 42 Harley St London