Ophthalmic electrophysiology is a series of tests that measure how different parts of your eyes and vision system respond to light. Ophthalmic electrophysiology tests are more involved than your usual eye exam. Talk to your healthcare provider or the test technician ahead of time to understand which type of test you’ll need and why.
Ophthalmic electrophysiology is a series of tests used to diagnose conditions that affect your vision. They measure how different parts of your eyes and vision system respond to light.
These tests check how your eyes and brain process what you’re seeing by measuring the electrical activity in your retina and optic nerves.
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Your healthcare provider will use ophthalmic electrophysiology to diagnose conditions that affect your vision, including:
Ophthalmic electrophysiology can also help your healthcare provider diagnose more general symptoms like:
Your healthcare provider might also use an ophthalmic electrophysiology test before recommending surgery on your eyes.
Trained technicians perform ophthalmic electrophysiology in a specially equipped lab.
Your healthcare provider will place electroencephalogram (EEG) disks on your face, eyes, head and scalp to read electric signals. Where EEG disks are placed depends on which type of ophthalmic electrophysiology test you’re having. The most common include:
On the day of your test, don’t wear or apply anything to your face or hair, including:
Bring your prescription glasses with you to the test. If you usually wear contact lenses, you’ll need to take them out before the test.
Your eyes may be dilated for the test, which might make it unsafe for you to drive yourself home. Ask your healthcare provider ahead of time if your test requires dilation, and arrange for transportation if needed.
Ophthalmic electrophysiology tests are more involved than most tests your healthcare provider uses to check your eyes. Tests can take up to three hours from start to finish.
If the technician needs to put electrodes on your eyes themselves, they’ll numb your eyes with drops before applying the electrodes. The electrodes might feel scratchy or strange, but it shouldn’t hurt.
You usually won’t have to do anything during the test itself. Listen to the technician’s instructions and let them know if you’re feeling any pain or discomfort.
If you needed numbing drops in your eyes — or if your pupils were dilated — it might take a few hours for your vision to return to its usual level. Don’t drive, use tools or any equipment that might hurt yourself or others while your vision is impaired. Don’t rub your eyes for a few hours after your test either.
Talk to your healthcare provider or the test technician about how you should care for your eyes after your test.
There are usually no risks involved with an ophthalmic electrophysiology test.
It’s rare, but there’s a small chance an electrode applied directly to your eye can scratch your cornea.
Your healthcare provider will get the results after your ophthalmic electrophysiology. They’ll let you know if the test detected anything out of usual ranges in your vision system.
The test results will help your healthcare provider know what next steps you’ll need to correct any issues the test identified.
Visit your healthcare provider if you notice any changes to your vision, including:
Go to the emergency room right away if you suddenly lose your vision.
A note from Cleveland Clinic
Your vision is precious to you, and it can be frightening to think something is wrong with your eyes. Needing an ophthalmic electrophysiology test doesn’t necessarily mean something is threatening your ability to see. The test will help your healthcare provider understand what’s causing any symptoms you’re experiencing, and what they need to do to help you maintain your eye health.
Last reviewed by a Cleveland Clinic medical professional on 02/16/2022.
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