A visual field test measures how much you can see around you. Ophthalmologists often use this test to diagnose and monitor eye problems.

To take the test, you sit at a device called a perimeter with one eye covered. When you see a light appear on a screen, you simply press a button. The test is repeated using the other eye.

Your ophthalmologist will tell you how often you should have a visual field test.

If you have any questions about your eyes or your vision, speak with your ophthalmologist. He or she is committed to protecting your sight.