Visual Field Test

Alternate Names : Perimetry, Visual Field Testing

The visual field test measures a person's vision in different areas. For example, it measures a person's side vision or up and down vision.

Who is a candidate for the test?

A visual field test is often done as part of a routine eye exam. Also, it may be used to diagnose serious diseases of the eyes or brain. For example, visual field testing is commonly done to help diagnose and monitor glaucoma.

How is the test performed?

There are a number of variations of this test. It can be performed by a healthcare provider or by a machine. When a provider does the test, he or she asks the person to look straight ahead. The provider then places his or her hand or an object somewhere in the field of vision. While the person looks straight ahead, he or she is asked if the hand or object is visible.

In the machine test, the person sits in front of a screen with one eye covered. The person is asked to focus the open eye on a central spot. Lights appear in various areas in the field of vision. The person is asked to respond if he or she sees the spots. Often, a person is asked to press a button when a spot appears. The person's responses creates a map of the visual field. Other versions of the test use different colors for spots and backgrounds or other shapes.