Board of Trade Lantern

A Lantern instituted in 1913 by the UK Navy following a lawsuit from a sailor who was being dismissed from his post after being identified as colorblind according to Holmgren’s Wool. The original lanterns used an oil lamp for illumination, but were replaced by electric lights in 1939.

The test has quite poor specificity, meaning that 8% of color normals would fail the lantern, and one study shows that the test only had 75% sensitivity, meaning only 3/4 of the color deficient failed it (Cole 1982). Considering that only 8% of all men are colorblind, this meant the test was actually failing more color normals than color blind (in absolute numbers)!