Farnsworth Lantern Test

Our Farnsworth Lantern Test, or FALANT, is a color vision tests initially developed for screening sailors for the tasks that need color vision.

What is Farnsworth Lantern Test?

The Farnsworth Lantern Test (FALANT) is one of the popular color vision tests developed for sailors to identify red-green deficiencies for completing their tasks requiring color vision, such as recognizing signal lights at night.

The test was invented by Dr. Dean Farnsworth (Commander, United States Navy) in 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 for sailors aboard ships, it was also used to screen flying personnel.

United States Federal Aviation Administration accepts the FALANT test to issue a pilot's license. After 1993, the United States Air Force discontinued the FALANT due to its failure to identify cases of color blindness considerably.

Now, FALANT is no longer manufactured, but many modern equivalents of various levels of sophistication are using lantern tests, like the Optec-900.


How does the Farnsworth Lantern Test Work?

Lantern Test shows a vertically oriented pair of lights consisting of red, green, yellow-red or green-yellow mixtures. The user is asked to recognize the difference between any two colors.

A total of Nine color pairs are used during the test, and It starts with a red/green color pair to allow the user to see these two colors pair before seeing a white light, which reduces testing errors.

The test only shows colors for a second, as color-deficient people can sometimes correctly identify the colors with prolonged exposure.

Yellow-white color or one of the identical paired yellow and white colors made a 50% neutral grey filter to reduce luminance cues to the color-deficient patient.