The Friedmann Visual Field Analyser Mark II--technical evaluation and clinical results.

The perimetric concept and the technical construction of the Friedmann Visual Field Analyser Mark II (VFA Mk II) were evaluated. This instrument for multiple stimulus static campimetry of the central 25 degrees is the successor of the Friedmann VFA Mk I. The number of stimuli is increased (99 vs. 47) and the console is improved. The positions of the presented stimuli are indicated on a LED-monitor. The mechanical and electrical construction of the VFA Mk II appeared to be good. 106 eyes of patients and normal subjects were tested and we conclude that the larger number of stimuli, though improving the chance of detecting small defects, complicates the manual registration and the interpretation of clinical results and prolongs the test, especially in the case of visual fields with substantial defects.