The Farnsworth Lantern Test, or FALANT, is a test of color vision developed specifically to screen sailors for shipboard tasks requiring color vision. It was developed by Dr. Dean Farnsworth while stationed at the Naval Submarine Research Laboratory in New London, Connecticut during World War II. After its adoption by the United States Navy in 1954 as the standard color vision test, it has additionally been used to screen aviators, as well as personnel who will serve shipboard.[1]
The test consists of showing lights of various colors to the test subject and asking him to identify the colors. At least nine color pairs are administered during the test. By design, the FALANT allows mild color-blindness conditions to pass the test, while still excluding the more serious cases of color-blindness. The test is intended to mimic the types of situations requiring color vision that a sailor would find while serving aboard a ship.
The FALANT is accepted by the United States Federal Aviation Administration as a test of color vision for the purpose of obtaining a pilot's license. However, the United States Air Force discontinued use of the FALANT in 1993 due to its frequent failure to identify cases of color blindness considerably more serious than the test was intended to let pass.
The original FALANT apparatus is no longer manufactured, but many modern equivalents of various levels of sophistication are available today.