Color vision in elderly individuals and in color-deficient individuals

Abstract

In this article, I describe the influences of age-related changes to the visual system on color vision in elderly individuals. The relationship between color recognition and color appearance is also discussed. The optical density of the ocular media, especially the crystalline lens density, increases because of aging. Light intensity at the retina in elderly individuals decreases by approximately one logarithmic unit in the short wavelength region compared to the middle wavelength region. This spectral change causes some errors in a color vision test using a digital display. However, a test that uses an anomaloscope is not influenced. In addition, the sensitivity of cone cells is reduced primarily by anatomical changes in the cones. These age-related changes are expected to cause relatively large changes in color appearance. However, the amplification of the S-cone signal to maintain the balance of cone signals in all types of cones and the color constancy effect contribute to the stability of color appearance in elderly individuals. In cyanopsia, which may occur when beginning to use a clear-type intraocular lens, long-term chromatic adaptation will also influence color appearance. However, color appearance and color recognition do not necessarily correspond to each other, based on the results of an experiment in deuteranopic observers using the method of bidirectional relationships between semantic words and hues. In elderly observers, color appearance and color recognition do not necessarily correspond, which is expected. Therefore, to understand color appearance by color names alone may be difficult.