Incidence of colour-blindness among the marine fishermen of Puri

Abstract

475 adult males from three endogamous groups ofmarine fishermen of Puri were examined for colour blindness using the 15th edition of Ishihara colour-blindness chart. The results are interpreted in the light of Post and Pick ford's hypothesis of selection relaxation, and the marine fishermen as a special ecological category.

Prevalence of Colour Blindness in Young Jordanians

“…Somewhat similar results were observed in marine fishermen of Vadabalija and Vadapeta tribes of the Puri Coast in India, which showed a ratio of 1.94. It is completely different from the Jalary group, which showed an equal ratio of deutan to protan types [11]. Filippi et al [25]found an incidence of 4.07% deutan colour blindness, but no protan visual defects were observed among 516 Mediterranean males from Sardinia in Italy having glucose-6-phosphate dehydrogenase deficiency.…”

“…Ishihara pseudo-isochromatic colour plates, a well accepted method for detection of a great majority of congenital red/green dyschromatopsias by many authors [4, 6, 8, 9, 11, 14, 15], were used to examine the ability of the students to recognize certain numbers in these plates [16]. One examiner was used to carry out the test for all subjects in the sample in a room with sufficient indirect daylight.…”

“…In his investigation on marine fishermen of the Puri Coast (India), Reddy [11]found that the incidence of colour blindness among fishermen does not exceed 5%. He also observed a very high deutan to protan ratio (3.81:0.96).…”

Análise psicométrica de um questionário para avaliação do impacto da alteração de visão de cores

“…Com relação à proporção entre os tipos de defeitos congênitos, deuteranopes e protânopes, os estudos encontraram relações semelhantes de deutan: protan de 3∶1 (Reddy, 1983) e outros uma proporção de 2∶1 (Al-Aqtum e Al-Qawasmeh, 2001). Mas em todos uma prevalência maior de deuteranopes.…”