A quantitative test of optokinetic nystagmus and its data processing by computer.

A quantitative test of optokinetic nystagmus was proposed. Horizontal nystagmus was examined by a large rotating cylinder with vertical stripes. Nystagmus responding to the cylinder rotation with an acceleration of 2 degrees/sec2 for 90 seconds was recorded with an electronystagmograph. On the records, the number of beats, average eye-speed, and average amplitude per each 10 seconds were calculated. This method was suitable for testing the nature of optokinetic nystagmus which indicates the ability of the eyes to adapt to objects moving through the visual field. Moreover, in order to save trouble in hand-scoring of each parameter of nystagmus, computer processing of electronystagmographic data was introduced. The results were printed numerically on the teletypewriter, and displayed graphically on a cathode ray tube and X-Y recorder. By displaying measured values on the form already printed with the normal ranges, the evaluation of the results was performed readily and objectively.