Screens are usually made for use at 1 or 2 meters. The method is simple. The traditional method is to attach the target to a black wand and move the target in from the periphery. The examiner stands next to the patient to observe fixation and works from each side of the screen in turn. The patient is positioned on the hemisphere-shaped machine with the chin on a chin rest and the uncovered eye is aligned with the central fixation point.
Fixation is monitored by the perimetrist through a telescope.
Projected test spots of constant size and fixed contrast are moved from the periphery in toward the center. The patient presses an electric buzzer when the target is in view. The method is straightforward and similar to kinetic perimetry. The patient is asked to fix on a central target in a hemisphere with a homogenous white background, while a non-moving light of fixed size and brightness is presented at various points in the hemisphere. Brightness is increased until the patient recognizes the presence of the stimulus above the background.