Image Analysis Tools to Quantify Visual Properties of Hair Fiber Assemblies 324 manifestations become. The quantification of synthetic hair dye deposition and its subsequent maintenance in hair is another area where such measures could be useful. Dye fastness in hair—whether the dye remains inside the shaft after multiple shampooing cycles or exposure to solar radiation—is a recurring problem in the personal care industry. In addition, in vivo color measurements of panelists in the salon would be much easier to accomplish with a digital camera than with a bulky spectrophotometer that only contains a small sampling area. The reader should be forewarned: taking a point-and-shoot approach to photographic quantification could lead down a disastrous route. There are some technical details we must consider. For example, each photograph should be color-calibrated by ensuring that a MacBeth color card is present in the photograph. Also, there are numerous camera settings that should be manually controlled including shutter speed, aperture, white balance, ISO, type of image file (preferably RAW), focus, focal length, etc. An even more paramount challenge is photographic lighting. Textural effects will certainly influence our perceptible shade of color. Therefore, any illumination must be exactly reproducible in order to avoid any shadowing effects imparted by the geometry of the fiber assembly or facial features in the case of whole head evaluations. In the near future, we should expect more reports in the literature offering guidance for such measurements. Analysis of Eyelashes Eyelashes protect the eye from debris and are found in almost all primates. They also serve as sentinels of sensation, warning our eyes that a foreign object is nearby. Eyelashes also play an important role in beauty and fashion. They are often treated with mascara formulations to enhance certain properties of the lash, making it more striking to the observer. Typically, the objective of an eyelash treatment is to increase volume (thicken), enhance curvature, and darken the lashes. There have been several research accounts on the subject of eyelashes or mascara treatments, primarily focusing on the physical attributes imparted on the eyelash by the mascara.60-61