Visual field test
The visual field test measures the area we are able to see directly in front of us (central vision), as well as, what is above, below or off to either side (peripheral vision).
Humphrey visual field, Goldmann visual field, Tangent screen
What to expect:
The visual field of each eye is examined one eye at a time. The appropriate lens correction is placed in front of the patient’s eye. The chin is placed in a chin rest, and the forehead against a support bar to keep the head still during the test.
The patient focuses on a central target to keep the visual field steady. Lights of differing brightness and size are presented in the patient’s visual field. The patient responds by clicking a buzzer. The test takes approximately 10 to 15 minutes per eye. The results generate a computerized printout for the physician to review.
What to do:
Visual field test results are most reliable when the patient is alert and well rested.
How the test will feel:
Patients may feel fatigued after the test due to the concentration required to maintain fixation during the test.
Why the test is performed:
A visual field test is performed to assess a patient’s central and peripheral (side) vision.
A normal visual field means that the patient can see well in the center and around the edges of the visual field.
What abnormal results mean:
Abnormal visual field results may reveal loss of side (peripheral vision) or central vision due to conditions such as:
- Macular degeneration
- Retinitis pigmentosa
- Medication toxicity (i.e., Plaquenil)