VEP/visual evoked potentials
It is a supportive diagnostic method used to assess damage to the visual pathway, for example in patients with optic neuritis. The examination is performed by a trained nurse. The patient sits and looks at a screen displaying a checkerboard pattern, alternating between the right and left eye. The responses are recorded using electrodes attached to the head.
The examination is not painful.
If you use glasses for distance vision, you must bring them with you. The results are evaluated by the physician.
FAQ
1. How does the VEP examination work and what will I do?
The examination is very simple and takes place while seated. The nurse will attach a few small surface electrodes to your head (in the occipital area at the back of the head, where the visual center is located) using a conductive gel. Then, we seat you in front of a monitor.
- Your task will be to watch a black-and-white checkerboard on the screen, which switches colors in a steady rhythm (black turns to white and vice versa).
- In the center of the checkerboard is a small dot (a red target) that you will focus on.
- The test is performed for each eye separately—we will temporarily cover one eye with a light patch.
2. Does the VEP examination hurt and is it safe for the eyes?
The examination is completely painless and safe. You only look at the monitor; no sharp or uncomfortable light flashes into your eyes, and the device sends no current into your body. Watching the checkerboard can fatigue the eyes after a few minutes, but the exam does not damage your eyesight in any way and has no side effects.
3. Do I need to remove my contact lenses or glasses?
On the contrary! If you wear glasses or contact lenses for distance (to read the monitor), you must bring them with you and wear them during the examination. For accurate results, we need you to see the checkerboard as sharply as possible.
4. How long does the examination take?
The measurement of visual evoked potentials is very quick. The entire visit, including attaching the electrodes to the back of your head and evaluating the results, takes approximately 20 to 30 minutes.
5. How should I prepare for the VEP examination?
No demanding preparation is necessary. You can eat, drink, and take your medications normally.
- Clean hair: Wash your hair with shampoo the night before or that morning. Do not use any hairspray, gel, or mousse, so that the electrodes hold properly on the back of your head. Please bring a towel with you.
- Eye drops: If you use artificial tears or eye drops, apply them well in advance so that your vision is not blurry during the test. Do not wear heavy eye makeup (mascara, eyeshadow) on the day of the exam, as it could irritate your eyes during steady focusing.