Definition of Electroretinography:

Electroretinography is a test to measure the electrical response of the eye's light-sensitive cells, called rods and cones.

How the test is performed:

While you are comfortably seated in a chair, the health care provider places numbing drops into your eyes, so you do not feel pain during the test. Your eyes are then propped open and an electrical sensor (electrode) is placed on each eye.

The electrode measures the electrical activity of the retina in response to light. A light flashes, and the electrical response travels from the electrode to a TV-like screen, where it can be viewed and recorded. The normal response pattern has waves called A and B.

The doctor will take the readings in normal room light and then again in the dark, after allowing 20 minutes for your eyes to adjust.

How to prepare for the test:

No special preparation is necessary for this test.

How the test will feel:

The probes that rest on your eye may feel like an eyelash. The test takes about one hour to perform.

Why the test is performed:

This test is done to detect disorders of the retina. It is also useful in determining if retinal surgery is recommended.