Eyes

Visual Fields

Some type of testing the visual field is generally used in every complete eye exam.

Your “visual field” refers to your peripheral vision…what you see around and to the sides of your central vision. When you look directly at something, its image falls on a part of the retina (inner lining of the eye) called the macula. But the rest of the retina “sees” as well. Just not as clearly. For example, focus on this X. Note that the X is clear. You are aware of the other letters, the page, your computer monitor, and the walls of the room. But they are not as clear as the X.

Some disorders can cause a loss of peripheral vision. The patterns of loss often help the physician in identifying the underlying problem. Thus, some type of testing the visual field is generally used in every complete eye exam. It may be as simple as looking at a checker-board grid, or using your side vision to see how many fingers an examiner is holding up. Other times, complicated and/or computerized equipment is used to map out the entire visual field. (Or parts of it.)

This sophisticated mapping of the visual field takes an amount of concentration, but is not painful. Your eyes are not dilated. Basically you are asked to focus on a central dot, then press a button on a hand control device when you notice other lights coming on in the periphery. The test can take anywhere from 5 to 20 minutes per eye.

Jan Ledford, COMT
EyeWrite Productions