Effects of using an orange filter on the color perception of dichromats

An orange filter (Kodak Wratten 23A) was placed over the nondominant eye of dichromats and evaluated for effectiveness in improving their color perception. A Macbeth color chart, rather than a standard Ishihara test, was used to test color identification. The filter did not improve color identification, but may, under specific color luminance conditions, improve color discrimination, resulting in an improvement in the detection of figure from ground.