Visual field tests are used as a method of measuring a patient’s complete scope of vision. Not only does this test the individual’s central vision, but it measures the strength of their peripheral vision as well.
The visual field test’s primary purpose is to examine each eye individually to detect blind spots in an individual’s vision. The visual field test can also help identify the causes of dim or worsening vision in the individual.
While the visual field test is a useful procedure for an eye doctor, it is an extremely subjective test. This means that the patient must be aware of the ‘why’ and ‘how’ of the test, and cooperate fully in order for the test to produce accurate results.
Why Should I Take a Visual Field Test?
Those who are at risk of vision loss or are developing a vision impairment should make a visual field test a routine part of their scheduled eye exams.
Visual field tests, if conducted appropriately can be instrumental in the detection of vision loss.
According to the American Academy of Ophthalmology, individuals with these conditions should be monitored by their ophthalmologist to determine how frequently they should conduct a visual field test:
- Multiple sclerosis
- Pituitary gland disorders
- Problems with the central nervous system
Additionally, visual field tests can be used to measure the extent of retinal diseases like retinitis pigmentosa, and can even help detect problems with the optic nerve.
If a defect is detected during a visual field test, it is common practice to repeat the test a couple of times, so the doctor can be certain that the defect was not simply an anomaly or a user error.
Different Types of Visual Field Tests
There are many successful ways to take a visual field test, with each type sharing some commonalities. For example, most tests are performed one eye at a time, with the other eye being covered to avoid errors.
Additionally, all tests require the test taker to look straight ahead without moving their gaze, as all tests need to accurately measure the peripheral vision.
The many different varieties of tests capitalize on different methods of detecting vision problems, and most use a different medium, or different parameters to create the best possible results for the patient.
Here are a few different types:
The Amsler Grid. This is a grid with a dot in the center that is printed on paper. The patient focuses on the center dot, and the lines of the grid serve to detect blind spots or abnormalities in vision.
Confrontation visual field testing. The doctor presents stationary and moving objects in the patient’s peripheral vision and the patient indicates whether or not they can see them.
Static automated perimetry. The patient focuses on the center of a large white bowl where flashes of light are periodically projected at different points of the patient’s vision. The patient presses a button to indicate the detection of these lights, and the data is collected electronically.
These are only a few of the many types of different visual field tests that help doctors detect vision problems all around the world.
If you have further questions about visual field tests, or think you may be due to take one yourself, contact your eye doctor today!