During comprehensive vision exams, eye doctors routinely check scope of vision, which includes the full horizontal and vertical range of central vision and peripheral (side) vision. This is accomplished with a visual field test.

Visual field tests measure the visual field of each eye, identify the presence of blind spots, and check for visual field abnormalities, all of which may indicate eye disease or brain disorders.

What is visual field testing?

When doctors refer to your field of vision, they are talking about how much you can see around you, including your side vision. The visual field test is designed to check for loss of side vision and diagnose eye problems and visual abnormalities.

These are basic visual field testing methods:

Moving target tests: During this test, lighted targets are moved from beyond your peripheral vision toward the center of your visual field. As soon as you recognize the target, you press an indicator button.

Fixed targets: Objects appear suddenly rather than moving from the side to the center of your vision. When a target appears, you press the indicator button.

Reasons for visual field testing

Countless eye and brain disorders can cause visual field abnormalities and blind spots in the field of vision.

Visual field testing is used to detect all of the following conditions and disorders:

• Glaucoma 
• Central or peripheral retinal disease 
• Ptosis (drooping eyelid) 
• Optic nerve disease 
• Macular degeneration 
• Toxicity from certain medications 
• Brain tumors 
• Stroke 
• Brain injury or swelling

Performing visual field tests

Visual field tests are performed on one eye at a time, with one eye temporarily covered to avoid errors. The tests can be done on a dark screen or on a wall using an instrument called a perimeter. Patients are asked to sit facing the testing instrument and look straight-ahead at a fixed spot. Lighted objects are introduced into the field of vision at different locations and varying intensities. Patients are instructed to push a button when they first see the target. The tests are simply and stress-free.

Your field of vision will be checked during a routine eye examination. If it has been two or more years since your last comprehensive eye examination, contact your optometrist today.