Abstract
The relationship between apparent darkening evaluated with the naked eye and age-associated changes in the physical properties of the skin (e.g., roughness or transparency) was clarified by defining two new physical properties: micro roughness and spectral transparency. Also, ways to quantify these properties were sought. The relationship between the degree of darkening, Y, discussed in the previous report and these two physical properties was investigated. The results showed that by adding these two physical properties (micro roughness and spectral transparency) to the existing parameters, namely the degree of coloring caused by melanin quantity, M1, and the quality of blood circulation and flow, M3. it was possible to more accurately and objectively quantify the degree of apparent darkening evaluated with the naked eye.
