¡¡¡¡DISCUSSION

¡¡¡¡According to our finding, about 0.4% of women had hereditary color vision deficiency, and most of them had problem in differentiation of redª²green color. The reports from different countries show 0.2%ª²0.5% of women have hereditary color vision defects (Table 1).

¡¡¡¡In Iran, Modarres et al[2] reported among 2058 students (1136 male, 922 female), nintyª²seven cases with color vision defects (93 boys, 4 girls) so 8.1% of boys and 0.43% of girls have had color vision deficiency. Three girls (0.32%) showed deuteranomaly and one girl (0.11%) protanomaly[2].

¡¡¡¡In Jordan, among 1200 female students, three cases showed color blindness (0.33%), two of them deuteranomaly, one protanomaly and one protanopia[3]. In Ethiopia, Zein reported among 1064 girls, two cases (0.2%) of color blindness[7]. In India of 519 female students, two cases were color vision deficient (0.38%)[8]. Rebato and Calder¨®n[9] from Spain reported 0.46% color vision defect in 218 female students and Cabrero et al[10] in 529 girls has reported no case. In singapore Chia et al[11] reported a prevalence of 0.2% in Singaporean children. This rate was 0.4% in Korean females[12].

¡¡¡¡In our study, the rate of hereditary color vision deficiency in female students was 0.63%, which is a little higher than other reports. However, it can be inferred that prevalence may be lower in unurbanized regions probably because of higher selection pressure working against the mutant allele in spite of urbanized regions with almost complete relaxation of selection pressure and hence higher allelic frequency about 0.05[13ª²15].

¡¡¡¡The ratio of deutan to protan was found to be very high in our study (1.66). Somewhat similar finding has described in other reports[1,16], but it was different from Filippi et al[17]. That found an incidence of 4.07% deutan, albeit in males, but no protan defect. However the type or severity cannot be completely inferred from "Ishihara pseudoisochromatic plates".

¡¡¡¡Although color vision defect in women is not common, but with increasing of women participation in social activities, especially in developing countries as Iran and entering of them in some jobs which need color vision[18], it is necessary for both students and politicians to know about this problem and appropriate future programming.

¡¡¡¡We recommend another study about both hereditary and acquired types of color blindness in whole population and different races, and because the rate of acquired color vision defect is equal in men and women, research about middleª²aged women may be useful.

¡¡¡¡¡¾²Î¿¼ÎÄÏס¿

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