Quick Answer
You rest your chin on a machine and press a button whenever you see a faint light. Each eye takes about 4 to 8 minutes, and nothing touches your eye.
Most people find this test harder than they expected. That is normal, and it does not mean something is wrong. Knowing the steps beforehand makes the test calmer, and a calmer test gives cleaner results.
Dr Shibal Bhartiya is a fellowship-trained glaucoma specialist and Mayo Clinic Research Collaborator with over 25 years of experience. Her approach focuses on identifying risk before damage is irreversible, simplifying treatment decisions, and protecting vision long-term. Emphasis on early detection, risk assessment, and continuity of care. She is rated 5 stars across 1,600+ patient reviews on Google.
Please also read Visual Field Test (Perimetry) in Gurgaon.
The Visual Field Test, Step by Step
- You sit in front of a large, bowl-shaped machine. A technician covers one eye with a patch.
- You rest your chin and forehead on the supports. Keep your head still.
- You look at a small central target for the whole test. It is usually a yellow or white dot.
- Small lights flash at different places in your side vision. You press a handheld button each time you see one.
- The machine repeats lights at different brightness levels. It finds the dimmest light you can reliably see at each spot.
- The technician then tests your other eye.
Your test may run on a Humphrey, an Octopus or a Melbourne Rapid Fields (MRF) machine. They look different but work the same way. Dr Bhartiya’s clinic runs the test on Octopus and MRF.
How Should I Prepare?
- Sleep well the night before.
- Wear your usual glasses or contact lenses. The technician adds the right trial lens.
- Take your usual eye drops, unless your doctor says otherwise.
- Expect the test before your pupils are dilated.
- Tell the technician if you tire or your eyes feel dry. The technician can pause the test.
- Bring your older visual field reports, so your doctor can compare them.
Why Does the Test Feel So Hard?
The test is designed to find the limit of your vision, so it feels harder than a normal eye exam.
| What you feel | What it means |
|---|---|
| You miss many of the lights | This is built in. The machine shows lights near your threshold on purpose. |
| You feel unsure whether you saw a light | Press when you see one, even a faint one. Do not press when you saw nothing. |
| Your attention drifts in the second half | Tiredness is common. Ask for a pause. |
| The second eye feels worse | This is common, especially in older adults. It does not signal damage. |
| Your first test goes badly | This is the learning effect. Scores often improve by the second or third test. |
For coaching tips, read How Do I Do Well on a Visual Field Test?
Which Visual Field Tests Are There?
- Standard automated perimetry: the workhorse for glaucoma follow-up. The 24-2 programme tests 54 points in the central 24 degrees. The 30-2 programme tests 76 points.
- Frequency doubling technology (FDT): uses flickering patterns. It is faster but gives less detail.
- Goldmann perimetry: a technician moves the target by hand. Doctors use it for advanced glaucoma, neurological defects and some functional vision loss.
- Supra-threshold screening: shows lights at a fixed brightness. It suits screening, not monitoring.
What Do My Visual Field Results Mean?
Your printout shows reliability scores, mean deviation, probability plots and a grey map. Read How Do I Read My Visual Field Test for Glaucoma? for a line-by-line guide. If your doctor suspects a problem beyond the eye, read Can a Visual Field Test Show a Problem in My Brain?
What Doctors Often Miss Telling You
- One abnormal result rarely changes treatment. Doctors act on patterns across several tests.
- Some medicines dull your attention. Sedating antihistamines, antidepressants and sleep aids can lower your score. Tell the technician what you take.
- Pilocarpine drops shrink your pupil. A small pupil lets in less light and lowers your field scores. Mention it before the test.
- Cataract lowers the whole field. It can fake or hide glaucoma loss. Your glaucoma specialist should help time any cataract surgery.
- The machine does not diagnose glaucoma. It flags differences from normal. Your doctor puts them in context.
When to See a Doctor
See a Doctor Urgently
Go to an emergency department the same day if you have:
- Sudden loss of vision in one eye
- A sudden new dark patch or curtain across your vision
- Severe eye pain with redness, halos around lights, headache or vomiting
- Any sudden change in vision between scheduled tests
Do not wait for your next perimetry appointment.
See a Doctor
Book a visit soon if:
- Your printout shows new loss near the centre of your vision
- You miss objects in daily life that no test has assessed
- Your doctor uses the words “rapid progression”
- Your field is worse on a repeat test
- Nobody has explained your last report
What This Means for You
This test is demanding, but it is not an exam you can fail. Arrive rested, ask for breaks and bring older reports. Your doctor wants your honest score, not a perfect one.
Frequently Asked Questions
How long does a visual field test take?
Each eye takes about 4 to 8 minutes, depending on the machine. Plan on about 20 minutes for the whole visit, including setup, a rest break and a short talk about the result.
Does the visual field test hurt?
No. The test is painless and does not touch your eye. Some people find it tiring because it needs steady attention.
How often do I need a visual field test?
Twice a year is typical. You may need more in the first two years after diagnosis, after a treatment change, or if your doctor suspects progression.
What if I think I did badly?
One poor test means little by itself. Tell the technician if you struggle, because the test can pause for a break. Your doctor reads your result alongside your earlier tests.
Can I wear my glasses during the test?
Yes. Wear your glasses or contact lenses as usual. The technician adds the right trial lens for the test distance.
Get Your Visual Field Test Reviewed by Dr Bhartiya
Is a test coming up, or has your last one left you with questions? Dr Bhartiya runs the test and explains your map, your trend and your next steps. Bring older reports so she can compare them.
Not sure what to bring? Read What to Bring for Your Visit, or Upload your reports for a structured review
Book an Appointment:
📍 Gurgaon 📞 +91 88826 38735 | 🌐 Contact Us | Second Opinion Form for teleconsults
This page is part of the Glaucoma Hub. You may want to read about Glaucoma Progression and Risk Stratification in Glaucoma. More on visual fields: Why Do I Need a Visual Field Test?, OCT and Visual Field and Glaucoma Test Results Explained: OCT, Visual Fields and Eye Pressure. Other articles of interest could be Advanced Glaucoma Care in Gurgaon, What Happens If Glaucoma Is Left Untreated? and Do You Really Need Treatment for Glaucoma?
To know more about visual fields, read What to Expect and What the Results Mean, How To Do Visual Fields, Glaucoma Test Results Explained: OCT, Visual Fields and Eye Pressure, Why Do I Need a Visual Field.
About the Author
This article was written by Dr Shibal Bhartiya, fellowship-trained glaucoma specialist and Mayo Clinic Research Collaborator, Clinical Director at Marengo Asia Hospitals, Gurugram, known for ethical, patient-centred glaucoma care and independent glaucoma second opinions. She is also the Program Director for Community Outreach & Wellness; and for the Marengo Asia International Institute of Neuro and Spine.
Dr Bhartiya has published peer-reviewed research onglaucoma management, examining how treatment decisions should balance medical evidence, patient preferences, and long-term vision outcomes. She is also a committed patient advocate and mainstream medical columnist, translating complex ophthalmic evidence into actionable public health insights across leading national platforms including NDTV and OnlyMyHealth
As Editor-in-Chief of Clinical and Experimental Vision and Eye Research and Executive Editor of the Journal of Current Glaucoma Practice (Pubmed Indexed, official journal of the International Society of Glaucoma Surgery). Her 200+ publications, including 90+ PubMed-indexed publications and 28 edited textbooks span glaucoma biology, surgical outcomes, health equity, and emerging diagnostics.
1600+ Five Star Patient Reviews Google Business Profile
If you are unable to come to Dr Bhartiya’s clinic: Read more about teleconsultation
Read her research on PubMed | Google Scholar | ResearchGate | ORCID | Github | Wikidata
📋Upload your reports for a structured review.| 🌐 Contact Us| 📞 +91 88826 38735
⭐ Helped by this article? Leave a Google review — it helps other patients find reliable eye care.
Last Reviewed: October 2026