Summarize this article:

For the visual field test, it’s important that you keep your eyes focused directly ahead. The doctor will stand about 3 feet (0.91 m) in front of you. They will hold out their hand about 1 foot (0.30 m) from one side of your face, and wiggle one of their fingers at the same level as your eyes. They’ll ask you to confirm that you saw the finger wiggle.  Testing your visual field involves making sure that your optic nerve correctly picks up and transmits visual data from your peripheral vision. It also determines if there are any lesions in your visual pathway. For a full visual field exam, the optometrist will test your optic nerve’s ability to gather visual data in each of the four quadrants of your peripheral vision: upper-right, upper-left, lower-right, and lower-left. The doctor will repeat the finger-wiggling exercise three times, and ask you to confirm that you saw the movement of their finger. If at any point you cannot see motion in your peripheral vision, let the doctor know. This may indicate a problem with your optic nerve. This is a further means of testing your optic nerve’s ability to pick up information in your peripheral vision. In a visual inattention test, the optometrist will hold out their hands as in a typical visual field exam, but they’ll wiggle more than one finger simultaneously. The doctor will ask you to identify how many fingers they wiggled and which specific fingers they were.

Summary:
Remain still and look straight ahead at the optometrist. Keep your eyes ahead while the doctor repeats the procedure. Ask the doctor about a visual inattention test.