A visual field test is part of a comprehensiveeye examand part of aneurological examination.
A visual field test can help diagnosescotomas, or blind spots.
It can also help identify loss ofperipheral or side vision.
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Loss of side vision is an indicator ofglaucoma, a disease that can lead to blindness.
Chakrapong Worathat / Getty Images
Annual visual field testing is usually covered byvision insurance.
For people who’ve been diagnosed with glaucoma, insurance may cover at least two tests per year.
If you are uninsured, discuss the costs upfront with your doctor.
What Is a Visual Field Test?
It can help identify scotomas or “blind spots.”
These are areas in the field of vision where you are unable to perceive an image.
Four quadrants are used:
A normal visual field measures about:
One eye is tested at a time.
This is because the visual fields of the eyes overlap.
Visual pathways carry information from the eye to the visual part of the brain.
There, the information is processed into vision.
This test can help diagnose diseases of the eye, optic nerve, and central nervous system.
Your vision relies on yourretina,optic nerves, and yourbrain.
Vision loss occurs due to diseases that affect any part of this pathway.
Who Should Have a Visual Field Test?
You should also request a visual field test if you believe you are having vision problems.
For people with healthy vision, visual field testing is part of a regular comprehensive eye exam.
The American Academy of Ophthalmology recommends regular exams at specific intervals based on age.
Types of Visual Field Tests
Methods for testing visual field vary.
Some simple screening tests can be done in a few minutes during a regular vision check-up.
Other tests are more complicated and comprehensive computerized tests.
Each eye is tested separately as the other eye is covered.
A machine presents flashing lights of different sizes and brightness in different parts of the visual field.
The machine gradually increases the size or brightness of the lights.
The patient pushes a button when the lights become visible.
The results of this test aren’t always perfect.
For that reason, this test is usually repeated two or three times in one session.
Because automated visual field testing machines are computerized, the test results can be tracked.
The computer can use certain calculations to rule out errors.
Kinetic Perimetry
During this test, the patient looks at a central point.
A light is presented in the peripheral vision and is moved toward the central point.
The patient pushes a button when the light becomes visible.
This test may be done on a screen or manually.
The manual technique is called Goldmann kinetic perimetry.
Kinetic perimetry may be used to find vision problems located in the central nervous system.
This includes visual changes brought on by a stroke oroptic neuritis.
Frequency Doubling Perimetry
During this test, a compact machine presents flickering images in varying intensities.
The patient presses a button when the images can be seen.
This key in of machine is also used to test for glaucoma.
Amsler Grid
The Amsler grid is a simple pattern of squares with a dot in the middle.
It is often used to test for central vision field problems.
During this test, the patient focuses on the dot with one eye at a time.
The Amsler grid is often used to test formacular degeneration.
Electroretinography
An electroretinogram is a test that measures the function of the retina.
Interpreting the Results of Your Visual Field Test
Test results are often presented in charts.
The charts may include:
What Happens After Your Visual Field Test?
If you have abnormal results, your healthcare provider may order additional tests.
Depending on your results, you may need to see a specialist, such as aneurologistor anendocrinologist.
The next stages of testing might involve brain imaging or blood tests.
Blood tests screen for conditions like:
Imaging tests may includebrain imaging, such as a brain MRI.
Sometimes visual evoked potentials may be ordered to assess nerve function.
Monitoring Glaucoma
Most types of glaucoma begin with loss of peripheral vision.
If you have signs of glaucoma, your healthcare provider will probably order a visual field test.
Summary
A visual field test is often done as a part of an annual eye exam.
The results of these tests can point to specific types of vision loss.
They can also help doctors monitor the progression of glaucoma.
There are a few different types of visual field tests, and they are all non-invasive.
Some are done manually; others are computerized.
Lestak J, Lestak T, Fus M, Klimesova I.Temporal visual field border.Clin Ophthalmol.
2017;100(4):313332. doi:10.1111/cxo.12551
BrightFocus Foundation.Glaucoma: understanding the visual field test.
American Academy of Ophthalmology.Eye exam and vision testing basics.
Wu Z, Medeiros FA.Recent developments in visual field testing for glaucoma.Curr Opin Ophthalmol.
2018;29(2):141-146. doi:10.1097/ICU.0000000000000461
Glaucoma Research Foundation.Why do I need a visual field test?
