The Incidence of Defective Color Vision Among Boys of Grade School Age
Abstract
INTRODUCTION For more than a century the facts of defective color vision have interested scientists working in the field of vision. Theorists must take cognizance of these facts in attempting any explanation of normal color vision. Perhaps even greater interest has been evinced by those working in applied fields where means of identifying individuals with faulty color perception have been sought as aids necessary for personnel selection. Results of a number of investigations lead us to expect that approximately eight per cent of the European male population and one half of one per cent of the female will be color defective in some degree. Deviations from the normal trichromatic vision can be divided into three main groups: monochromatism, or total inability to see hue; dichromatism, a reduction in color sensitivity to the point at which all colors seen can be matched by a mixture of only two hues; and anomalous trichromatism. A person with anomalous trichromatic vision can, like the color normal, match all hues with a mixture of three non-comple- mentaries, yet must have more than the normal amount of one of these in order to correctly match certain color mixtures. These categories are further subdivided on the basis of characteristic luminosity functions into protan, deutan, tritan, and tetartan. The first two denote the more common red-green defects; the last two are the names of rare blue-yellow weaknesses. Protanopes and deuteranopes are di- chromats lacking the ability to distinguish red and green. A unilateral dichromat studied by Graham and Hsia (3) was able to see only varying brightnesses of blue and yellow with her dichromatic eye. It is presumed, then, that the protanope and deuteranope see the world only in variations of blue and yellow except at characteristic neutral points where all chromatic perception is lacking. The protanope is distinguished from the deuteranope because of a darkening of the red end of the spectrum for the former, Deuteranomaly, or green weakness, and protanomaly, or red weakness, are the more frequently occurring defects.
Subject Area
Ophthalmology
Recommended Citation
Leonard, Mary John Catherine, "The Incidence of Defective Color Vision Among Boys of Grade School Age" (1959). ETD Collection for Fordham University. AAI28673344.
https://research.library.fordham.edu/dissertations/AAI28673344
