Visual Field Test: What You Need to Know
A visual field test is a subjective gauge of the quality of a person’s central and peripheral vision. The purpose of the test is creating a separate map for each eye. This details its field of vision and identifies potential blind or weak spots.
A basic, or confrontation visual field test consists of the doctor instructing the patient to look straight ahead. The doctor judges the response to manipulating targets within the patient’s peripheral vision. Doctors also use an Amsler grid, which judges visual scope from a printed image.
A computerized visual field test uses flashes of tiny dots of light within a spherical screen. Each eye is separate. Doctors instruct patients to look straight ahead and click a button when they see a flashing dot of light. A computer uses this feedback by creating detailed maps of the patient’s peripheral vision.
The kinetic perimetry test, also known as a Goldmann perimeter, is an additional computerized visual field test. This test focuses on capturing a map of the entire perimeter of the normal scope of vision. This test utilizes moving light flashes of varying sizes, with the patient clicking as they become visible.
The most common use of the visual field test is searching for early signs of glaucoma. It is also used to detect if glaucoma causes damage to the optic nerve. Loss of peripheral vision serves as an early indicator of glaucoma. The visual field test is also useful for effectively monitoring response to glaucoma treatment. Computerized visual field tests are the most useful for these diagnostic and monitoring purposes.
Visual field tests also detect other eye conditions, such as ptosis (drooping of the eyelid) and diseases of the retina. They see damage to the optic nerve due to other medical conditions. They detect conditions that impact image transit from the optical nerve to the brain. Visual field tests see a toxic response to certain medications and other factors.
In cases of temporary or permanent vision loss, visual field tests help identify one of the causes in order to seek the most effective treatment.
Who Provides Visual Field Testing?
An ophthalmologist usually performs medical visual field testing, but a neurologist can also do this.
If you notice vision loss, schedule an appointment with your local eye doctor, who will give you a full examination and then determine if you need visual field testing. At the Dr. Myers Eye Care Center, we offer advanced computerized visual field testing along with decades of experience treating glaucoma and symptoms of vision loss.