Purpose of Performing a Visual Field Test:

The purpose of the visual field test is to assess the sensitivity of the eye as well as to determine if a patient has areas of diminished peripheral vision and if so, to what extent. The Humphrey Visual Field analyzer performs a thorough non-intrusive evaluation of the patient’s visual field to determine if patient has any visual field problems. Visual field testing provides information critical to the diagnosing and monitoring of neurological and ocular diseases, such as glaucoma.

The retina is the light sensitive tissue at the back of the eye that converts light waves into neurological signals, which are then transmitted to the brain. The retina is comprised of many light sensitive cells that allow the healthy eye to see objects around the point that we are focusing on. This ability to see things off to the side of objects we are looking directly at is referred to as ones peripheral vision or “the field of vision”. If an area of the retina, or the optical nerves associated with a specific region of the retina, are damaged or not functioning correctly, we may have “blind spots” or diminished vision in certain areas of our peripheral vision.

What Happens during Visual Field testing?

Each eye is tested separately. To setup for the test, one will place their chin on a chin-rest. In performing the Visual Field test one will be handed a “clicker-button”. You will be asked to press a clicker-button each time you see a flash of light and the machine records what you see. During the testing you are presented with a series of flashing lights on a bowl-shaped screen. The lights may vary in brightness and will appear in different positions in your field of view. The machine checks each point several times, so if you make a mistake the machine should be able to correct for this.

How Long Does The Visual Field Test Take?

This varies from test to test. Typically a ‘screening style’ test takes about 5 minutes.  More comprehensive testing, generally referred to as “Full Threshold Testing” make take anywhere from 7 minutes to approximately 20 minutes.