Reading time: 4 min
VISUAL FIELD TEST GDAŃSK INFORMATION ABOUT THE TEST: 
A visual field test involves plotting the visual field on charts, showing the area seen when the eye remains still. The visual field is the set of points in space perceived at the same time as the fixation point towards which the visual axis is directed. Analysing successive tests makes it possible to monitor changes in the visual field over time. Patients with glaucoma should have the test at least once every six months. The normal visual field of each eye is approximately:
- Towards the temple: up to 85º-90º
- Towards the nose: up to 55º-60º
- Upwards: up to 45º-55º
- Downwards: up to 65º-70º
Description of the test
A visual field test requires a high level of concentration and close cooperation from the patient, as the visual field is plotted based on their responses. The patient sits in front of the illuminated semicircular bowl of the perimeter, with their head held still by resting their chin and forehead on special supports. One eye is covered. Throughout the test, the patient must look at a point in the centre of the bowl, directly in front of the eye being tested. This is essential for the test to be performed correctly. A light stimulus of a specified diameter and intensity appears elsewhere on the perimeter bowl. The patient’s task is to report, without looking away from the central point, whether the stimulus is visible, is fading or has disappeared completely. The examiner marks these responses on a chart and, if necessary, repeats the test, changing the diameter, light intensity and colour of the moving stimulus. Connecting the marked points with the same parameters produces lines known as isopters, which define the extent of the visual field. The test takes from a few to several dozen minutes.
Purpose of the test
This test shows any visual field defects, including their location and size, on a chart for each eye separately. These most commonly correspond to areas of the retina where light stimuli are not perceived because of disease affecting the retina itself or disruption of the pathways carrying stimuli to the visual centres in the brain. Computerised visual field testing is used to diagnose glaucoma, all types of pathological changes in the eye and damage to the visual pathways. Visual field testing is therefore very important in diagnosing damage to the visual system and in locating other intracranial abnormalities.
Indications for the test
- Professional drivers, pilots, machine operators
- Nervous system disorders (especially those affecting the brain)
- Optic nerve disorders
- Glaucoma
- Retinal detachment
- Retinal and choroidal diseases.
Preparation and contraindications for the test
No special preparation is required for the test. However, it requires a high level of concentration and close cooperation from the patient, as the visual field is plotted based on their responses. For this reason, the test is not performed in young children, people with intellectual disabilities or older people who are disoriented. An important aspect is selecting the appropriate test method for the condition suspected in the patient. It is therefore advisable to have a referral from an ophthalmologist specifying the appropriate test method. If there is no referral, the person performing the test will select an appropriate method after discussing this with the patient. Near-vision glasses (reading glasses) are also helpful during the test for patients who use them.
Waiting time for results
The visual field test result is provided as a written report with an accompanying chart on the day of the test.
Where and how can you have the test?
Visual field testing is available at many healthcare facilities in Poland.
