The use of films to simulate age-related declines in yellow vision.

One of characteristics of normal age-related vision losses depends on yellow-intensity in the lens of the eye. (1) We investigated discrimination between seven intensities of yellow in 303 elderly people aged from late 60s to early 90s. The results demonstrated that the failures of vision increase with age, and the losses depend on yellow intensity. (2) We got a yellow index (YI) from different Y-intensity color charts used in (I) above, covering 12 kinds of marketable yellow films, and selected two kinds of films which match (YI) original color charts, corresponding to 53% or 89% of Y intensity. (3) Finally, we judged that all of these colors' xy-chromaticities with or without the two films, were exactly on the unique-yellow line in the diagram, which means a pure yellow, not mixed. (4) Then, these two films could simulate each of the mid-level or high-level Y intensity, respectively, in age-related vision. (5) We analyzed changes of all kinds of colors (220) in xy-chromaticity diagrams and obtained mean changing distances from every original chromatogram compared to the others. These data would be useful for architects or designers to design cities or buildings for use by the elderly.