Visual Evoked potentials VEP

Visual Evoked Potentials (VEP)

What is an VEP examination?

This is a test of the optic nerve which is the pathway between the eye and the back of the brain.  You will be asked to look at the centre of a television screen that has a moving black and white chequer-board pattern.  Each eye is tested separately, with a patch covering the other eye.  The test takes approximately 45 minutes to complete, and your results will be sent to the referring GP/clinician and are usually available within seven days.


How is the test performed?

The test is painless.  The test is performed by attaching some small discs to your scalp which record the electrical responses from your brain.  There will be 3 leads at the back of your head, one behind each ear and two on the top of the head.  The leads are attached with a sticky white paste which washes out of your hair easily.


You will be asked to concentrate on the centre of a pattern on a screen for 2-3 minutes at a time, each eye is usually tested twice.


How do I prepare for the test?

If you wear glasses please bring them with you, and ensure your hair is clean and free from hairspray and oils. 


If you are taking any medication, please continue to take it and bring a list of your medication with you.  You may continue to eat meals as normal.


There are no side effects from this test.