Visual Field Testing
A visual field test measures the range of your peripheral or “side” vision to assess whether you have any blind spots (scotomas), peripheral vision loss or visual field abnormalities. It is a straightforward and painless test that does not involve eye drops but does involve the patient’s ability to understand and follow instructions.
An initial visual field screening can be carried out by the optometrist by asking you to keep your gaze fixed on a central object, covering one eye and having you describe what you see at the periphery of your field of view. For a more comprehensive assessment, special equipment might be used to test your visual field. In one such test, you place your chin on a chin rest and look ahead. Lights are flashed on, and you have to press a button whenever you see the light. The lights are bright or dim at different stages of the test. Some of the flashes are purely to check you are concentrating. Each eye is tested separately and the entire test takes 15-45 minutes. These machines can create a computerized map out your visual field to identify if and where you have any deficiencies.