Automated detection of foveal fixation by use of retinal birefringence scanning

Foveal fixation was monitored in normal subjects remotely and continuously by use of a noninvasive retinal scan. Polarized infrared light was imaged o nto the retina and scanned in a 3 degrees annulus at 44 Hz. Reflections wer e analyzed by differential polarization detection. In all 32 eyes studied, the detected signal was predominantly 88 Hz during central fixation (within +/-1 degrees) and 44 Hz during paracentral fixation. Phase shift at 44 Hz correlated with the direction of eye displacement. Potential applications o f this technique include screening for eye disease, eye position monitoring during clinical procedures, and use of eye fixation to operate devices. (C ) 1999 Optical Society of America. OCIS codes: 070.6020, 120.5410, 170.4460 , 170.4470, 330.4300, 330.2210.