Eye monitor: microcomputer-based instrument uses an internal mode to track the eye

An eye monitor whose design is inspired by the human visual system is presented. The monitor incorporates an internal representation or model of what the eye looks like to a video camera. The system can measure the position of the eyes and the size of the pupil in the presence of interfering noise and in patients wearing eyeglasses or contact lenses, and it tolerates defocusing due to small movements in depth by the patient. The system makes real-time correction for head and eye movements while measuring pupillary responses to controlled light stimuli. The design and software and hardware components are described, and some applications are noted. Its use for early clinical detection of visual diseases by objectively measuring pupillary responses to carefully controlled light stimuli is examined as an example. Some general observations about using computers in medical measurements are made.<>