This test is designed to detect areas of loss of vision or reduced sensitivity to light. Defects in the visual field may go unnoticed for a long period, for example, in conditions of chronic glaucoma and pituitary tumours. Many optometrists now routinely check a patient’s visual fields with a screening programme as part of eye examinations.
We use the sophisticated ‘Humphrey Analyser’ software programme which is specifically designed to assess and monitor various eye and neurological conditions. For example, it is the mainstay for assessing conditions such as chronic open-angle glaucoma. This is where a patient’s central vision may be good, but other areas of their visual field may be restricted.
The Humphrey visual field test is designed to identify early changes to the visual function of the eye for both monitoring of conditions and in diagnosis, for example, of cerebral tumours or vascular events.
The test works by displaying flashes of light with a fixed background light level. This helps us to find the dimmest light that the patient’s eye is able to detect at various locations in the visual field.
Each eye is generally assessed separately with the other eye patched over. The entire test lasts up to 25 minutes.
We use the Estermann Test to assess the visual field of both eyes which the Driver and Vehicle Licensing Agency (DVLA) requires patients who are known to have areas of visual field loss to undertake as part of their application to hold, or continue to hold, a UK driving licence.