[OPTICAL REVIEW Vol. 8, No. 1 (2001) 64-70]

Computerized Simulation and Chromatic Adaptation Experiments Based on a Model of Aged Human Lens

Katsunori OKAJIMA and Masanori TAKASE

Department of Applied Physics, National Defense Academy, 1-10-20, Hashirimizu, Yokosuka, Kanagawa, 239-8686 Japan

(Received May 26, 2000; Accepted November 29, 2000)

Color appearance seen by old people does not signifiantly differ from that seen by young subjects even though their ocular lens has become more yellow with age. We calculated the age-related change of lights reflected from Munsell color chips onto the retina, and derived results that show that the chromaticity values of all the color chips shifted to the yellow region of the xy-chromaticity diagram. However, a replot on the CIELAB diagram and the estimation by means of the von Kries adaptation model suggests that old people may compensate their color vision using a general chromatic adaptation process. To test this hypothesis, we conducted two experiments: a chromatic adaptation experiment and a color matching experiment to simulate D65-lights as seen by older people but using young subjects. The results indicate that chromatic adaptation does not provide a complete explanation for color compensation by older people, suggesting that an age-related change of the yellow-blue opponent color mechanism may contribute to this compensation.

Key words : aging color vision, color appearance, chromatic adaptation, color matching, unique white, yellow filter, neural compensation, opponent color channel, von Kries model