Abstract
The eye lens and the macular pigment have been treated to be transparent for the long wavelengths. On the other hand, the observer variations of the color matching functions (CMF's) suggests that the lens and the macular pigment have unneglisible densities in the long wavelengths. In the present paper, improved values for the optical densities are proposed on the basis of the observer variation of CMF's. First, the principal component analysis is applied to the red CMF's of Stiles' 20 observers. The first eigen vector and the second eigen vector correspond to the spectral density functions of lens and macular pigment, respectively. Improved values of densities of lens and macular pigment are defined by connecting the published data of densities with the corresponding eigen vectors. Next, CMF's of Stiles' 20 observers are estimated by using the improved values of densities. It is confirmed that these estimated CMF's fit well the measured CMF's for the X component of CMF compared with the estimated CMF's from the published data though there is not an appreciable improvement for the Y and the Z component. Finally, the method of singular value decomposition is applied to the estimated CMF's from the improved densities. Deviate functions derived agree well with the deviate functions based on the measured CMF's.
