An iris feature detector (110) includes a reflexive eye movement source (112-1124); a multiple image sensor (118); a controller (120), and a processor (122). The controller (120) causes the eye movement source (112-114) to cause rapid eye motion, and the sensor (118) to capture first and second iris images over a time interval in which only an iris can move in the first and second images. The processor (122) determines differences between the first and second images. The sensor (118) may be integrated with the processor (122). The integrated sensor/processor is not limited to iris feature detection, and may be used for edge detection for machine vision and other applications.