A software package is described that collects and reduces eye behavior data (eye position and pupil size) using an IBM-PC compatible computer. Written in C language for speed and portability, it includes several features: (1) data can be simultaneously collected from other sources (such as electroencephalography and electromyography); (2) logically defined events can be detected in real time on any data channel; and (3) either of two types of data matrix can be produced. Data reduction algorithms and data structures are described. (Five tables of data describing aspects of the software package are included.) (Author/RS)