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The human visual system changes with aging and one of the most important changes is the decrease of spatial contrast sensitivity. We investigated this change both for luminance contrast and chromaticity contrast, and both for threshold contrast and preferred contrast, (preferred by users to carry out a visual recognition task), in a series of psycho-physical experiments with achromatic and chromatic sinusoid gratings of different values of spatial frequency, hue, and luminance level, and with two observer groups: young and elderly observers. We investigated the spatial frequency range of 0.1–10 cycles per degrees. Our results indicate that, beyond the expected luminance contrast sensitivity decline of the elderly observers, the difference between the preferred luminance contrast of the elderly and the preferred luminance contrast of the young is even more significant than the threshold difference. The small preference differences between the age groups for chromaticity contrast compared to luminance contrast suggests that while with increasing age both the chromatic and the achromatic contrast sensitivity drops, preferred contrast stays more stable for chromaticity contrast than for luminance contrast. |
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