This paper discusses the possibility there is a difference between men and women in foveal tritanopia. The discussion is based on a study carried out by Cobb and McCrossan in 1973 in which they measured the luminosity curves of the fovea in five women and five men. The instrument used was a Wright colorimeter which measured the luminosity curves with a 2 degree 12' field and a 0 degree 12.5' field. Comparison shows a loss of sensitivity to blue for the curve obtained with the 0 degrees 12.5 relative to the curve obtained with the 2 degree 12' field. Male subjects obtained two maxima with the 0 degree 12.5' field, usually at 555 nm and 595 nm, whereas for females on maximum, usually at 555 nm and from 555 nm to the long wavelength end of the spectrum, curves followed loosely the curve obtained with the 2 degree 12' field. Thus, a significant difference was found between the males and the females in their response to the longer wave-lengths when the 0 degree 12.5' (0 degree 12.5') field was used. In addition to this there were also large individual differences in the matching points obtained by the males while the differences among the females were much smaller.