VEP/ERG Tests
Visual Evoked Potential Test
A Visual Evoked Potential (VEP) test measures the electrical activity in the vision system. When light from an image enters your eye, it is converted into electrical energy at the retina and travels through the optic nerve to the visual cortex of the brain which processes vision.
The test involves applying a small number of electrodes to your head using paste. You will be asked to watch a TV screen or flashing light. Each eye will be tested separately. This will take approximately 45 minutes.
ElectroRetinoGram Test
An ElectroRetinoGram (ERG) is a harmless investigation and involves placing a number of small discs on your head and threads on your bottom eye-lids to record the electrical activity of your eyes. You will be asked to watch a TV screen and flashing lights.
The procedure may take 2-3 hours to complete.
You will probably have some eye drops administered which may blur your vision for up to six hours.
You will be unable to drive home after the test. Please do not wear makeup on the day of your test.
It is important that your hair is clean and free of hair products. It would be helpful if you could wash your hair the night before the test and you will probably need to do so again after you return home.