Categorical color naming of surface color codes by people with abnormal color vision.
OBJECTIVE
Past investigations of the ability of people with color vision deficiency (CVD) to name the colors of surface colors have been occupation-specific. This study was undertaken as a more generalized investigation to explore particularly the effects of stimulus size and shape.


METHODS
One hundred CVD observers and 20 color vision normal (CVN) subjects named the colors of two sets of surface colors, each set presenting the same 10 colors (red, orange, brown, yellow, green, blue, purple, white, gray, black). One set presented dot stimuli in three sizes (2.4 degrees , 1.0 degrees , 0.27 degrees ) and the other line stimuli with three widths (0.50 degrees , 0.27 degrees , 0.14 degrees ). Color vision was diagnosed using the Ishihara test, the Farnsworth D15 test, the Medmont C100, and the Nagel anomaloscope.


RESULTS
All CVN subjects and 37% of CVD subjects made no errors. Type of CVD and stimulus size were significant factors for probability of error and the effect of stimulus size is best described by 1/area. There were significant interactions between CVD type and 1/area and between shape and 1/area. Deuteranomals who passed the Farnsworth D15 test made significantly fewer errors than all other CVD types and 70% made no errors. Their common errors were to confuse red, orange, and brown. Protanomals who passed the Farnsworth D15 test made fewer errors than dichromats.


CONCLUSIONS
Mild deuteranomals will make very few errors with a seven-color code that omits orange, brown, and purple and will make very few errors (approximately 0.3%) with a 10-color code when the stimuli are reasonably large (area >20 mm).
Cole
Barry L
BL
Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia. bcole@optometry.unimelb.edu.au
Lian
Ka-Yee
KY
Sharpe
Ken
K
Lakkis
Carol
C
D000293:Adolescent; D000328:Adult; D002648:Child; D003118:Color Perception / Q000502:physiology*; D003119:Color Perception Tests / Q000295:instrumentation*; D003117:Color Vision Defects / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D012720:Severity of Illness Index