Study On The Differences Of Cone Fundamentals Between Young And Old Observers

Human color vision exists not only in color-deficient population,but also among people with normal color vision,especially for different aged observes.As the age increases,there will be a series of changes in all parts of the human eyes,including the retina,lens and ciliary body,which will lead to the phenomenon of"presbyopia".The difference in color discrimination is especially significant between young and old observers.The color matching functions?CMFs?recommended by CIE to represent the visual characteristics of average human eye color is no longer sufficient to characterize the spectral responses of cone cells among individual observers.In order to study the difference of cone cell response between young and old population,a color difference comparison experiment based on printed colors and a color matching experiment based on display colors were carried out respectively using the metameric samples.In the color difference comparison experiment,20 pairs of metameric color samples were prepared to highlight the observer variability in color discrimination,the young and old observers were organized to carry out the experiment.The obtained results showed that there was a negative correlation between the visual evaluation results of young and old observers.At the same time,visual data were used to test the performance of different CMFs.It was found that S2 and S6 CMFs proposed by Sarkar performed better for the young group,while for old observers,CIE1931CMFs were more suitable.Due to the larger viewing field in this experiments,CIE1964CMFs was used to do optimization and the new BIGC_Young and BIGC_Old CMFs was established correspondingly for young and old groups.The calculation results show that BIGC_Young and BIGC_Old CMFs have been improved and they perform better than the results of original CIE1964.The visual perception characteristics of metameric samples with different color patterns was further studied.Two display devices with great difference in primary spectra were selected in the color matching experiment,young and old observers were also organized to carry out color matching experiments between these two displays based on 5 color centers recommended by CIE.The results show that there are some differences between young and old observers in the values of matching color differences and the size and direction of the colorimetric ellipse in different color centers.Furthermore,Monte Carlo method and individual observer model were used to optimize and establish individual CMFs for each observer based on the experimental results.It was found that the color difference of young observers were not optimized,which suggests that CIE1964 CMFs are relatively suitable for young observers.While the results of 11 old observers were optimized and finally their CMFs were established,and the spectral distributions of new established individual CMFs for each old observer are in good agreement with those of BIGC_old CMFs.