Binocular infrared oculography.

A new system of infrared oculography has been developed which provides binocular recordings and allows simultaneous measurement of horizontal and vertical eye movements. The sensitivity of the system is 1 minute of arc, and it has a horizontal range of +/- 30 degrees and a vertical range of +/- 20 degrees. Using this system for routine clinical evaluations, it was possible to record divergent spontaneous nystagmus and divergent thermally induced nystagmus. Rotatory nystagmus can also be recorded. The binocular infrared oculographic system (BIRO) satisfies nearly all the requirements of an ideal recording system.