Abstract

The Farnsworth Dichotomous Test for Color Blindness (Panel D-15), often called simply the D-15 test, is an easy to administer arrangement test which is designed to fail those individuals having severe color discrimination loss. The test is very successful at detecting and classifying congenital dichromacy or anomalous trichromacy in which color discrimination is very poor. Because the test is readily obtainable and is easy to administer and score, it often is used to ascertain visual loss due to acquired defects or changes. When used in this manner, either tritan errors (those errors associated with a decrease of blue cone mediated discrimination) or errors associated with a diffuse loss of chromatic discriminative ability are of interest. This paper discusses briefly the relationship between these types of errors and blue cone sensitivity as measured with a threshold task in a population of normal individuals aged sixty and older.

© 1986 Optical Society of America