Your visual field is how wide of an area your eye can see when you focus on a central point. Visual field testing is one way we can measure how much vision you have in either eye, and how much vision loss may have occurred over time.
Many conditions can affect your visual fields. The Humphrey VFA test is the gold standard perimetry test used in hospitals to aid diagnosis and monitor glaucoma, and gives a very accurate picture of the visual field. We also use the Humphreys to perform the Estermann visual field test, which is the test required by the DVLA to assess the standard of visual fields needed for driving.