Peripheral vision is what you see out of the corner of your eye while you are looking at something in front of you. Peripheral vision may also be called side vision or, more commonly, your visual field. Testing peripheral vision is part of a normal eye exam and is called a confrontational visual field exam, according to the National Institutes of Health. More advanced testing may be required if you have an eye disease that causes vision loss.

1. Sit down and cover one eye, either with your hand or a handheld device, as instructed by your eye care professional. This is the beginning of the confrontational visual field exam, a non-invasive way to test your peripheral vision.

2. Look straight ahead at your doctor. You will be asked to tell him when you see a specific item in your periphery while you are still keeping your eyes on a focal point in front of you. The item may just be his hands, or he may be holding up a number of fingers for you to identify. Tell him as soon as you begin to see something in your peripheral vision, so he will know if you have lost any side vision.

3. Measure your peripheral vision with the use of a machine-operated test called an automatic perimetry test. All About Vision describes the procedure, explaining that you will see flashes of light in your visual field, and must indicate through a button when you see the lights in your side vision. Not all eye doctors will have an automated perimetry machine; you may be asked to do a manual confrontation visual field test or an automated exam.

4. Undergo advanced testing if you are diagnosed with loss of some of your peripheral vision. Eye diseases such as glaucoma can cause this kind of vision loss. An electroretinogram tests your peripheral vision through the placement of probes on your cornea. Flashing lights measure how your eye respond to the stimuli and gives a better picture of your eye's overall health.