title: Frequencies of different types of colour vision defects in the Netherlands.
abstract: Two different population samples in Holland--one consisting of 1,093 boys from a technical school and the other of 493 male and 416 female students--were analysed for the presence of red-green colour vision defects. A total percentage of 7.3 for the male population was found. Based on the combined results of the Ishihara and HRR pseudoisochromatic plates, the Farnsworth 15-hue test and the anomaloscope, a subdivision of the deuteranomalous individuals into 3 subgroups is made. It is suggested that the differences between these groups may be genetic in nature and that the actual number of different genetic entities may still be greater.
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003119:Color Perception Tests; D003117:Color Vision Defects / Q000453:epidemiology* / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D009426:Netherlands; D010375:Pedigree