The eye’s visual field is the entire area that can be seen while looking at a specific point, from the center to the far periphery in all directions. Certain diseases- particularly glaucoma, retinal disease, and neurologic disorders- can cause loss of certain parts of the visual field, typically in patterns fairly specific to the type of disease. Testing the eyes’ visual fields can therefore provide very useful information towards diagnosing or monitoring treatment of numerous conditions.
Visual field testing is conducted in the office using the Humphrey® Field Analyzer/HFA II-i, a computerized device capable of performing accurate, relatively quick exams. The testing procedure is as follows:
- Dilation is usually NOT required for this test.
- Information, such as your name, age, and certain ocular measurements, is entered into the computer.
- Each eye is tested individually. The eye not being tested is covered with a patch.
- Sit at the device with your forehead and chin comfortably positioned against rests.
- The technician performing the test will give you instructions, and will ask you to look directly ahead at a fixation target throughout the entire procedure.
- The device will begin to present a pattern of flashing lights. When you see a light you will press the button on the controller in your hand. Press the button only when you truly see the light- do not pay attention to sounds made by the computer.
- Most test programs will adjust the pace to your personal response speed- do not feel rushed. If you begin to feel tired or are uncomfortable, the test can be paused at any point. Simply ask the technician for a break.
- When the test is complete you are free to go. Results will be mailed to you after your doctor has reviewed them, and will be discussed at your next visit.
- This test typically takes about 20 to 30 minutes to complete.