Abstract

The United States Air Force (USAF) and Navy (USN) use a battery of tests to quantify depth perception, including the Armed Forces Vision Tester (AFVT) stereopsis test, AO Vectograph, Verhoeff, and Howard-Dolman (HD). Most of these tests are tests of stereopsis, such as the AFVT and AO Vectograph. Others evaluate depth perception with stereo as a contributor to performance, such as the HD. The USAF and USN maintain depth perception standards for pilots and other aircrew with scanner duty (e.g., aerial refueling operators, aircrew responsible for clearing aircraft during landing, etc.). However, very little research has been carried out to establish quantitative relationships between clinical tests of vision and operational aircrew performance, including clinical tests for depth perception, which is the goal of the USAF Operational Based Vision Assessment program. While the need for stereo vision for tasks involving distance estimation seems intuitive, research examining the role of stereo vision and/or stereo displays often fails to show a clear relationship. Further, the results of different depth perception tests often differ substantially. Thus, any research examining the importance of stereo vision must also take into consideration the adequacy of the screening test. This paper provides a review of the research on the role of depth perception in performance as well as different methods of assessing stereo acuity. Research plans at the USAF 711th Human Performance Wing, U.S. Naval Aerospace Medicine Research Unit, and DSO National Laboratories involving depth perception and stereo acuity test methods are described.