Abstract: A microprocessor based instrument designed to retrofit into existing perimeters utilizing the mechanics and stimulus control aspects of the existing perimeter. The device includes an array board positioned adjacent the perimeter mechanical arm and includes a multiplicity of visual indicators spatially arranged in a composite pattern of testing locations required for one or more ophthalmic testing procedures. A processor is connected to the array board for sequentially actuating the visual indicators in accordance with the testing procedure whereby the operator guides a cursor attached to the perimeter mechanical arm to align with the actuated indicators and control the location of the perimeter test stimulus. The processor includes means for sensing the position of the cursor, silently presenting a light flash to the patient, and a memory which records the patient's responses.

Abstract: First and second electro-optical display devices for displaying visual acuity targets, one of which is adapted to be viewed by a patient and the other of which is adapted to be viewed by an examiner. An electronic memory is connected to the display devices containing a plurality of acuity targets stored in various orientations for presentation to the display devices. Controls are provided in an examiner's console for selecting one of a plurality of available target sizes, "zoom" increasing size or decreasing size, selecting a single or a line of multiple target characters, providing normal or reverse video presentation, changing the orientation of the target characters, and providing a blank screen. The size of the targets is varied by changing the dimensions of each of the targets about its own center and in the case of multiple targets, maintaining proportional spacing between the targets as the size of the targets vary.