1. Eleven colour-blind subjects diagnosed as red-blind by routine procedure with Prof. Ishihara's charts were subjected to spectroscopic examination as developed by Prof. Hukuda and described in a previous report. 2. Of 11 subjects, all male, one was trichromic, 6 tetrachromic, 2 pentachromic and 2 were hexachromic in the sense of Edridge-Green. 3. All of them had sensation of yellow and blue. Expansion of the yellow zone to both &des, espcially toward the region of shorter wavelength was a most common feature. The green region was often sacrificed for the yellow. 4. Of 22 eyes, 4 had no zone of defective saturation while 7 eyes were characterized with two zones of defective saturation. This trait was not always represented symmetrically in each individual. 5. Two zones, instead of a single zone, of maximum brightness were reported by 14 eyes out of 22. 6. The spectrum was not always shortened at its end of longer wavelength. Some subjeets were suspected of shortening atits end of shorter wavelength.
1. An inhabitant, 19 year-old male, of Sado Island, and his sister, 16 years of age, were found to posses all conventional criteria of total colour-blindness. Spectroscopic examination, however, revealed they had more on less rudimentary colour discriminative power. 2. The brother was dichromic, his spectrum being composed of“ darkened blue” (Up to 495mμ) and “darkened khahki” (550. 700mμ) with a zone of minimum chromaticity at 495.550mμ. The sister was found trichromit. She saw the spectral range up to 485mμ as “darkened blue”. From 485mμ to 500mμ was minimum in chromaticity. A “darkened yellow” began at 500mμ and farther ahead it blended into a “ darkened red”, which continued up, to 690mμ. Possibility is indicated that the totally cokiur-blind generally retain rudimentary colour sensation, since previous cases had been diagnosed as such without spectral perusal, such as performed by the present authors. Hereditary relation was also discussed.
Twenty-two cases of trichromats as diagnosed by conventional technique were subjected to spectral examination in which their colour sensation in reference to wavelength in the continuous spectrum of incandescent daylight lamp was determined. Of the 22 male cases, one possessed a spectrum consisting of two principal colour zones, “yellow” and “blue”, i. e. dichromic in the terminology of Edridge-Green. Four proved to be tetrachromic with red, yellow, greeri and blue, or red, “orange”, blue and violet. Another four were pentachromic with red, orange, yellow, green and blue (three case), or red, “violet”, yellow, green and blue (one case). Remaining 13 cases were hexachromic with red, orange, yellow, green, blue and violet. It was then inferred that all eyes, even the dichromic were able to make out yEllow and blue ift the spectrum. Wave-length range of each discriminated principal colours varied from case to case. Inter-lateral difference was also present, although in a lesser extent A most markei characteristic common to all cases examined was deviation with expansion of the yellow range. In 4 cases among the hexachromic, point of transition between yellow and green was labile, showing fluctuation. In a case apparently normal in colour distribution in the spectrum on the first glance, yellow range expanded toward green, at a partial sacrifice of the latter in a few seconds. Four cases showed the reverse condition. Chromic feature of their spectrum at first was anomalous with an expanded yellow zone. When the gazing was continued a few seco id, the transition point between yellow and green shifted toward yellow side. Anomalous arrangement of the subjective spectrum thus resulted. As for subjective luminosity, 17 eyes out of 44 (22 cases) were reported to have two summit distribution. Twenty-nine eyes of 44 is reportei to have an unsaturated zone in the spectrum. It is generally situated in the neighbourhood of 500±5mμ. Some of the cases here reported, when subjectied to examination with an anomaloscope, showed a typical dichromatic pattern, while they were often found polychromic by direct spectroscopic examination, or more than two principal colour zones were differentiated.
Fifteen atypiCal cases of colour-defectives- as diagnosed with Professor Ishihara's international pseudbchromatic charts were subjected to the authors' techniqueof spectral examination as well as anomaloscopic investigation. Also in these case the at there' previous observations and statements' were' con-firmed without exception. Conventional class fication of colour-defectives into protanopia, deuteranopia, protanomaly and deuteranomaly was not based on a sound. ground of directive investigation of phenotypes.
Six pedigrees of non-tasters were recorded and the mode of inheritance was discussed. They conform with conventional theory of simple Mendelian recessive inheritance. In a pedigree were found three (two male and a female) non-tasters of very low manifestation. Possible interpretations for this anomaly were discussed and an assumption of incomple manifestation in heterozygous subject was offered as the simplest interpretation.