Full Field Electroretinography (ffERG) Vision Testing
Full field electroretinography (ffERG) is a highly-advanced vision test that objectively measures how well your vision system is working. The results of this ERG test will help your doctor diagnose various vision disorders, as well as better understand when changes in your visual function occur.
What is a full field electroretinography (ffERG) vision test?
The Diopsys® ffERG vision test is a painless, safe, non-invasive way for your eye care provider to objectively measure the function of cells in your retina – the light-sensitive layer at the back of your eye.
When light from an image enters your eye, it is turned into electrical energy by cells in the retina. The ffERG vision test, sometimes referred to as flash ERG or flicker ERG, uses flashes of light as a visual stimulus to elicit an electrical response from those cells. The electrical energy created is measured by the Diopsys® ffERG vision test, and used to create a report for your doctor. It is similar to an EKG, but for your eyes.
How do I prepare for an ffERG test?
Your face should be clean, dry, and free of any gels, sprays, oils, or lotion.
How is the Diopsys® ffERG vision test done?
A technician will clean and dry the skin under your eyes and on your forehead, and then place sensory pads on the recently cleansed areas.
The technician will then hand you a small dome that will be placed over your eye for testing. He or she will instruct you to use the dome to cover your right eye first, so that your eye is centered in the face of the dome. You will also be instructed to fixate your non-covered eye on an object in the room, such as a door knob or picture on the wall. Once the test begins, you will see a series of flashing lights. The computer will record your eyes’ response to the light and produce a report for your doctor.
Play the video below to watch an example of a Diopsys® ffERG vision test.