What Is a Visual Field Test?
A visual field test, sometimes called perimetry, maps the full extent of what each eye can see while you look straight ahead. It is a non-surgical, non-invasive diagnostic investigation rather than a treatment, and it causes no discomfort to the eye.
The most commonly used method in UK hospital and clinic settings is automated static perimetry. You sit comfortably in front of a bowl-shaped instrument, rest your chin on a support, and focus on a central target. Small lights of varying brightness appear at different points in your peripheral vision, and you press a button each time you notice one. The machine records which points you detect and which you miss, producing a detailed map of your visual field for each eye separately.
The results are shown as a grid or greyscale image, along with statistical indices that compare your results with the expected values for your age. Repeated tests over months and years allow your consultant to see whether the visual field is stable or changing, which is often more informative than any single test in isolation.
Who May Benefit From a Visual Field Assessment?
A visual field test may be recommended if you fall into one of the following groups, although your clinician will advise based on your individual assessment:
- You have been diagnosed with glaucoma or ocular hypertension and require ongoing monitoring
- Your optician has noticed a suspicious optic disc or raised eye pressure
- You have a first degree relative with glaucoma, which increases your own risk
- You have noticed gaps, shadows or blurred areas at the edges of your vision
- You are experiencing unexplained difficulty with tasks such as driving, reading or judging steps and kerbs
- You have a neurological concern such as persistent headaches, a pituitary problem, or a history of stroke affecting vision
- You are taking a long term medication that requires periodic monitoring of the visual field
- You need documented evidence of your field of vision for DVLA purposes
Importantly, many people with early glaucoma have no symptoms at all. Peripheral vision loss can develop so gradually that the brain compensates for it, which is why objective testing is so useful.
Conditions a Visual Field Test May Help Detect or Monitor
- Glaucoma: characteristic patterns of peripheral loss are a key part of diagnosis and of judging whether the condition is progressing
- Ocular hypertension: raised eye pressure without established nerve damage, where field testing helps confirm the optic nerve is still functioning normally
- Acute angle closure and narrow angle conditions
- Retinal disorders affecting specific areas of the retina
- Optic nerve conditions, including inflammation or compression
- Neurological conditions affecting the visual pathways behind the eye
Cataract can also reduce test performance by dimming and scattering light, so results are always interpreted in the context of your overall eye health. Patients considering cataract surgery, often have field testing as part of a wider assessment.
Potential Benefits of Visual Field Testing
Used appropriately, a visual field test may:
- Help detect changes in vision that you are not yet aware of
- Support an accurate diagnosis when combined with other investigations
- Provide a baseline against which future tests can be compared
- Help identify whether glaucoma is stable or progressing, which can influence treatment decisions
- Support conversations about driving safety and daily function
- Help avoid unnecessary treatment where the visual field remains healthy
A visual field test does not restore vision or treat disease. Its value lies in the information it provides, which can support earlier intervention and more tailored long term management.
Consultation and Assessment Process
Your appointment with Ms Diana Urbaneja typically begins with a discussion of your symptoms, general health, medications, and any family history of eye disease. A full ophthalmic examination follows, which may include visual acuity testing, eye pressure measurement, examination of the front of the eye, and a dilated view of the optic nerve and retina.
Where clinically appropriate, imaging such as OCT is performed alongside the visual field test. Once all results are available, your consultant will explain what they show, discuss the possible diagnoses, and outline the options. Where treatment is indicated, the benefits, risks and alternatives are discussed so that you can make an informed decision. Options may range from monitoring alone through to eye drops, laser treatment such as selective laser trabeculoplasty, or minimally invasive glaucoma surgery, depending on your diagnosis.
How the Test Is Performed
The test is carried out in the clinic and requires no anaesthetic, injections or eye drops for the field test itself, although drops may be used for other parts of your examination.
- One eye is covered while the other is tested, then the process is repeated for the second eye
- You rest your chin and forehead against the machine and focus on a central fixation point
- You press a handheld button whenever you see a light appear anywhere in your vision
- Each eye usually takes around five to ten minutes, depending on the programme used
It is normal not to see every light, and there is no pass or fail. Concentration matters, so if you feel tired you can ask for a short pause. Bring your glasses, as an appropriate lens may be used during testing. Because the test relies on your responses, results can occasionally be unreliable on a first attempt, and a repeat test may be requested. This is common and not a cause for concern.
After the Test and Ongoing Monitoring
There is no recovery period after a visual field test and you can drive and return to normal activities immediately, unless dilating drops have been used, in which case your vision may be blurred and light sensitive for a few hours and you should arrange alternative transport.
Results are usually reviewed during the same visit or at a follow up appointment. If you have glaucoma or are being monitored as a glaucoma suspect, repeat field tests are typically arranged at intervals determined by your risk level and the stability of your condition. You should seek prompt advice if you notice sudden vision loss, severe eye pain, redness with haloes around lights, or a rapidly expanding blind spot.
01
Test
Peripheral vision mapped, eye by eye
02
Review
Results discussed with your consultant
03
Monitoring
Repeated over time to track change
Guide Price
Price TBC
Often included as part of a consultation. See the pricing page for standalone test costs.
At a glance
Duration
~15-20 min per eye
Preparation
None
Results
Reviewed with your consultant
Next steps
Repeated periodically to monitor change