The study has shown that there is an appreciably greater frequency of defective color vision among the mentally retarded children in the counties specified than that found in normal children. The general objective of this study was to determine the frequency of color blindness among mentally retarded children in an area of northwest Iowa. The subjects were children in fifteen special education classes for the mentally retarded. The Hardy-Rand-Ritter Pseudoisochromatic plates for detecting, classifying, and estimating the degree of defective color vision were used in this study. The author in all cases did the examining.
Proceedings of the Iowa Academy of Science
©1964 Iowa Academy of Science, Inc.
Penniman, Terry L.
"Study of the Frequency of Color Blindness Among Mentally Retarded Children in the Counties of Buena Vista, Cherokee, Ida and Sac.,"
Proceedings of the Iowa Academy of Science, 71(1), 418-420.
Available at: https://scholarworks.uni.edu/pias/vol71/iss1/61