Visual field testing uses a white light to measure the extent of both the central and peripheral vision.  A central visual field is used to evaluate the macula.  The macula is the area responsible for seeing fine detail.  The peripheral visual field is used to evaluate your side vision and any glaucomatous changes.

In automated perimetry, stimuli are presented in a randomized fashion as the visual fields are explored.  Different test patterns are chosen based on the patient s ocular or neurological condition.  In order for this test to be reliable, patient cooperation is crucial.  The field analyzers have a normative patient database built into the instrument s computer for comparison.  This database is divided by age, since the sensitivity of the visual field declines with an increase in age.