Sweep Visually Evoked Potentials (sweep VEP)

Sweep VEP is an automated way to objectively assess visual acuity using proven visually evoked potential (VEP) techniques. It can be used to examine unexplained visual loss, cortical visual impairment (CVI), and to provide an objective acuity assessment when subjective ones are questionable or unreliable in pediatric and adult patients. 

Objective visual acuity assessment

The person sits in front of the monitor with three electrodes on their occipital cortex and one on their forehead. One eye is patched while the monitor displays several patterns with differently sized checks. Attention-getting devices and pause/resume features can be used on children who cannot reliably fixate.  

Sweep VEP stimulus

Visual acuity is determined by making the stimulus check sizes progressively smaller until the VEP amplitudes become near zero. The objective is to reduce the check sizes until the person’s visual system can no longer differentiate between the black and white on the screen. At this point, the estimated visual acuity is automatically calculated. No response is required by the patient during the test.