The overlapping-monoculars instrument was developed as a result of a study program concerned with wide angle viewing devices for tanks. The instrument is a binocular eyepiece device supplying to the user an undistorted horizontal field of view of 140° and an undistorted vertical field of 90° thus providing what is believed to be the closest approach yet achieved to the fixated field of unaided human vision. The discussion includes fundamental theory of the device, optical design criteria, and a description of the performance of the system.
Martin Shenker, Joseph LaRussa, Paul R. Yoder, Jr., and Wright H. Scidmore, "Overlapping-Monoculars—An Ultrawide-Field Viewing System," Appl. Opt. 1, 399-399 (1962)