“…Hakkinen (2004), for example, stated that the occurrence of rivalry with a monocular HWD results in an annoying and straining experience for the user. In military applications, binocular rivalry is suspected to contribute to the visual problems, noted previously, associated with the U.S. Army's Apache helicopter IHADSS (Behar et al, 1990) and to decrease the visibility of flight symbology in the U.S. Air Force JHMCS (Winterbottom, Patterson, Covas, Rogers, & Pierce, 2006;Winterbottom, Patterson, Pierce, & Taylor, 2006).…”