What is a Visual Field
The visual field is the entire area that can be seen when the eyes are focused on a single point. In addition to what can be seen straight ahead, the visual field includes what can be seen above, below, and to either side of the point the eyes are focused on. Vision is typically best in the middle of the visual field.
A visual field test is performed as part of the eye examination. Visual field testing assists in determining where your peripheral vision (i.e., your side vision) begins and ends, in addition to how well you can see objects in your peripheral vision.
The visual field can be tested in a few different ways, including the confrontational visual field exam, tangent screen test, and automated perimetry exam. One or a combination of these tests may be conducted to examine your visual field.
The results of these tests will determine which areas of your visual fields you are having trouble with, as well as possible causes for these difficulties.
Visual field testing is important in the diagnosis of glaucoma, and as a means of determining progression of glaucomatous damage. VF loss may precede, be concurrent with, or follow, optic nerve damage in the early stages of glaucoma. Once diagnosed, visual field testing is important for monitoring glaucoma progression.