A Visual Field Test is done to help diagnose and or detect any possible effects of loss of vision, glaucoma, disorders of the retina, stroke, brain tumors, diabetes and more. The actual test is a procedure that measures how much peripheral or ‘side’ vision you have. It is done by sitting in front of a computer and does not require any eye drops. During the exam, you look into a monitor, resting your chin on a chin rest to keep your head still. Lights are flashed on and off, and you have to press a button whenever you see the light. The lights are bright or dim at different stages of the test. Each eye is tested separately and the entire test takes 15-30 minutes. The doctor will review the results of the test with you either during the exam or in a follow-up visit to the office.