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Visual fields

Visual field (peripheral vision) testing is used to help diagnose and monitor conditions affecting the optic nerve or the visual pathway. Typically, we test patients who are attending the hospital for their glaucoma or neuro-ophthalmology appointment, though many other patients can be required to undertake the test. We use a Humphrey visual field machine and the test is supervised by a technician.

What to expect

  • The visual fields testing room is dimly lit in order for the Humprey field analyser (HFA) to work correctly.
  • Before entering the visual fields room, please have ready whatever eye correction you use. This could be your varifocals, reading glasses, bifocals or contact lenses. The technician will ask you which glasses you have and may ask to take them to measure the prescription.
  • You will be in a seated position for the entirety of the test and the technician will ensure you are positioned correctly before providing test instructions.
  • There will be other patients in the room conducting their assessments.

Keeping your results reliable

  • Maintain your gaze on the fixator light(s) at all times during the test.
  • Only press the response button when you are sure you see a light appear other than the fixator.
  • Your head must remain in the same position for the entirety of the test. Please refrain from tilting, turning or leaning your head backwards.

Frequently asked questions

What is a Humphrey visual field test?

A Humphrey visual field assesses the sensitivity of your vision. It does this by showing you small white lights of varying intensity and recording when you see them.

Why am I having a Humphrey visual field test?

You may be referred to the hospital by your optician and based on this referral we would like to find out what a visual field test can tell us about your vision. This test determines your sensitivity to light in different areas of your retina. There are a wide range of reasons you are being asked to perform the test (for example, glaucoma screening and / or monitoring or checking reduced vision). However, the objective is that the clinician can determine whether your visual field test result is normal.

Why do I need to do the test more than once?

Subsequent tests help to monitor your eye condition. This informs the healthcare professional how to proceed with your continued eye health.

What can you tell from the test?
  • The test measures sensitivity across your field of vision.
  • It can indicate how your field of vision may be changing.
  • It indicates whether or not you have a normal visual field.
How long does the test take?

A standard test takes between 4 and 8 minutes but this varies patient to patient.

Do I need my glasses?

It is important to bring any glasses that you currently use with you as you will need them at various points throughout your ophthalmic review.

I only have one affected eye; why does my good eye need testing as well?

It is important that both eyes are monitored carefully in order to detect any changes that may occur.

Will all the lights be the same brightness?

No. The brightness will vary throughout the test in order to accurately determine your visual sensitivity.

What happens if I click by mistake?

It is unlikely that one or two mistakes will affect the test. However, it is important to only click when you see a white light in order to produce a result with the best possible reliability.

Can I close my eye under the patch?

Yes, you can have your eye closed or open under the patch, whichever makes you more comfortable.

Can the room temperature be altered? It is too hot / cold?

Yes, the room is often air conditioned due to the heat generated by the machines. If you are cold then please speak to the technician who will adjust the temperature accordingly.