What is a visual field test?

Why do I need a visual field test?

A visual field test helps your eye care professional understand your peripheral vision. Your peripheral vision is often called your side vision but can actually refer to any part of your vision outside central vision – what you see when you look straight ahead.

Peripheral vision loss can be a symptom of vision conditions such as glaucoma, so regular visual fielding testing can be very useful for early detection. If you are already diagnosed with an eye condition, your eye care professional may use visual field testing to monitor its progression or determine which parts of the eye have lost visual field sensitivity and how this field loss is affecting your peripheral vision.

If you have an existing eye condition, a visual field test may also be required for you to renew your driver's license. Your eye care professional can let you know if this is necessary and how often it may be required.

People who have experienced a stroke may also experience issues with their peripheral vision, including blind spots (scotomas), homonymous hemianopia or quadrantanopia. Your eye care professional can also use a visual field test to diagnose these vision changes and monitor your recovery.

What happens during a visual field test?

• You will sit close to the visual field machine and rest your face against the bowl-shaped device (sometimes called a barrel).
• One eye is patched at a time, so each eye is tested separately.
• You will hold a clicker button in your hand.
• If your eyelids are drooping and blocking your vision, let the technician know - they may be able to apply tape to gently hold your eyelid up.
• Focus on the small light at the back of the bowl and keep fixated on it throughout the test.
• The machine monitors your eye position. Looking away from the central light too often can affect the accuracy of your results.
• You can ask for a short break at any time if you need one, say ‘pause’.
• Each eye takes around 5–10 minutes to test.
• Small lights of varying brightness will flash at different points around the bowl.
• Click the button each time you see a light, even if it’s very faint.
• Your results will show a map of where you missed lights, which highlights any areas of reduced peripheral vision.

For people who have significant peripheral vision loss, such as people with advanced glaucoma or retinitis pigmentosa, or people who have experienced a stroke, an eye care professional may use a method called confrontation visual field testing. This means your eye care professional will sit opposite you and move their hand slowly inward from an outstretched position until you can see the hand in your peripheral vision. Confrontation testing is less accurate but can be useful for detecting larger patches of missing vision.

For more information

• Read our article on ‘What is glaucoma?’.
• Read our article on ‘Understanding vision changes after a stroke’.
• Read our article on ‘What is retinitis pigmentosa?’.
• Always speak to your eye care professional about the best treatment options for you.