Visual evoked potential (VEP) test

Your consultant physiologist will explain the diagnostic test to you. Your eyesight will be checked and you'll be asked to read an eye chart. Electrodes will be attached to your head using sticky paste. One of your eyes will be covered with an eye patch. You'll see a TV screen with a moving pattern of black and squares displayed on it you'll be asked to focus on this for a few minutes. The physiologist will record the movements of your eye as you watch the screen. Each eye is tested. The test takes about 30 minutes to one hour.

There is no specific preparation for visual evoked potentials test, but make sure your hair is clean and that you bring glasses or contact lenses with you if needed.

The electrodes will be removed from your head using warm water. The test results will be analysed, and the results delivered to your consultant the following week. Your consultant will request a follow-up appointment and will explain the results to you.