Upper eyelid morphology and age-related changes in Japanese and Chinese females.

BACKGROUND: Many consumers use cosmetic eye products to counteract age-related changes in appearance. Measurements of eyelid shape in Asian women have been reported in the frontal view or 45-degree profile only. The aim of this study was to describe morphological characteristics of the upper eyelid in Japanese and Chinese females from the frontal and profile aspects and examine morphological changes with age. MATERIALS AND METHODS: Standardized digital photographs of 772 Japanese and 346 Chinese women (15-79 years of age) were acquired in frontal and 90-degree profile aspects. Eleven upper eyelid parameters (e.g., width, length, depth, aperture, and curvature) were measured using image analysis to determine age-related changes and compare by ethnicity. RESULTS: Eyelid width, area between eyebrow and eyelid, and eyelid curvature were comparable for both ethnicities under age 40, but the aging effect was more pronounced in Chinese subjects. Eyelid height, depth, and upper eyelid aperture angle were also comparable for both ethnicities under age 40, but the aging effect was more evident in Japanese subjects. Upper eyelid incline angle, eye orientation, and upper eyelid protrusion angle changed comparably with age for both ethnicities. No prominent age-related changes were evident for eyelid length or area between eyebrow and eye with the eye closed. CONCLUSION: Upper eyelid morphology changes with age in Japanese and Chinese females, starting around 40 years of age. Ethnic differences are limited in younger age groups but become more prominent with age. The findings suggest that aging affects some upper eyelid features earlier than others.

Video-based paired comparison to evaluate some cosmetic products under camera movement for dynamic performance.

OBJECTIVE: Until now, standardized evaluation of cosmetic effects was conducted mainly in still conditions such as pictures. In real life, the consumers' experience of their cosmetics' effects is dynamic and some of the benefits can be better observed under movement. In order to capture motion-related performance of cosmetics, we developed a video-based paired comparison on an online platform. METHODS: We validated this new tool through the evaluation of eyeshadow with high light reflection and colour gradation, especially visible under motion according to the observer point of view. This formula was compared with two marketed benchmarks. The three products were applied sequentially on the eyelid of eight Japanese women. Videos were taken in standardized light, speed and face position with a rotating camera around the face. The videos were uploaded on an online secured platform and eyelid 3D effect, highlight and colour gradation were evaluated through paired comparison test by 60 Japanese women from home on their PC or tablets. Those results were compared with picture-based paired comparison by the same observers. RESULTS: Video-based paired comparison provided higher discrimination of products compared to picture-based comparison. CONCLUSION: As compared to still camera acquisition, the evaluation of cosmetics based on videos is closer to real-life experience and can bring higher discrimination, especially for motion-related attributes.

OBJECTIF: Jusqu'à présent, l'évaluation standardisée des effets cosmétiques a été réalisée principalement dans des conditions immobiles telles que des photos. Dans la vie réelle, l'expérience des consommateurs des effets de leurs cosmétiques est dynamique, et certains des avantages peuvent être mieux observés en mouvement. Afin de saisir les performances des produits cosmétiques liées au mouvement, nous avons mis au point une comparaison par paires basée sur des vidéos sur une plateforme en ligne. MÉTHODES: Nous avons validé ce nouvel outil en évaluant un fard à paupières à forte réflexion lumineuse et à gradation de couleurs, particulièrement visible en mouvement selon le point de vue de l'observateur. Cette formule a été comparée à deux références commercialisées. Les trois produits ont été appliqués successivement sur la paupière de huit femmes japonaises. Les vidéos ont été prises dans des conditions de lumière, de vitesse et de position du visage normalisées, avec une caméra tournant autour du visage. Les vidéos ont été téléchargées sur une plateforme sécurisée en ligne, et l'effet 3D des paupières, l'accentuation et la gradation des couleurs ont été évalués au moyen d'un test de comparaison par paires par 60 femmes japonaises depuis leur domicile sur leur PC ou leur tablette. Ces résultats ont été mis en parallèle à une comparaison par paires sur photo par les mêmes observateurs. RÉSULTATS: La comparaison par paires sur vidéo a permis de mieux distinguer les produits par rapport à la comparaison sur photo. CONCLUSION: Par rapport à l'acquisition d'images fixes, l'évaluation des cosmétiques à partir de vidéos est plus proche de l'expérience réelle et peut permettre de mieux distinguer les produits, en particulier pour les attributs liés au mouvement.

Repeatability and reproducibility of a hyperspectral imaging system for in vivo color evaluation.

BACKGROUND: Color imaging is a tried and true method for the evaluation of cosmetic and dermatological effects, but it fails to capture all the information in a scene's spectral reflectance. For this reason, there has been in recent years increasing interest in the use of imaging spectrometers for clinical studies and product evaluation. MATERIAL AND METHODS: We developed a novel HyperSpectral Imager (HSI) able to take in vivo full-face format images as a next generation instrument for skin color measurement and beyond. Here, we report part of the results of our first full-scale validation test of the HSI. We replicated a make-up foundation screening test by applying three products to a panel of 9 models and evaluated the product L∗ , a∗ , b∗ , and ∆E effect immediately after application relative to the bare skin condition. We repeated this test twice in order to study the repeatability of the HSI as an evaluation instrument and during each test two different operators duplicated the data acquisition so we can assess the reproducibility of the measurements. RESULTS: We find that the measurements from the HSI provide repeatability and reproducibility as good or better than those of our previous benchmark devices. CONCLUSION: From these results, we conclude that not only is the HSI suitable for use in color evaluation studies, but also that it gives operational advantages over the previous generation of evaluation instruments, as it provides a spectral measurement combined with good spatial resolution. This allows for analysis of color over an area and post hoc selection of study regions and so opens new possibilities for studies of complex in vivo phenomena which neither non-imaging spectrometers nor conventional cameras can pursue. This study also raises points for future work concerning proper inclusion of instrument uncertainty in comparisons of results between instruments and handling of systematic uncertainties from analyses based on a single area.

A preliminary study to understand the effects of mask on tinted face cosmetics.

BACKGROUND: The recent COVID-19 pandemic has generalized the use of face mask in public area, and it is now common to wear it for long hours. But face mask interfere with cosmetics, and key concerns for tinted products are staining of the mask and degradation on face. Consumers have modified beauty routine by a decrease of makeup, but are now expecting new products adapted to face mask. Little is known about the mechanisms that affect most the makeup under the face mask, so that further studies are needed to develop adequate evaluation methods and products. In this study, the color transfer on mask and makeup degradation on face are assessed through a mixed approach of consumer and instrumental evaluation. MATERIALS AND METHODS: Two tinted face products (A and B) were applied by half face on 11 Japanese women, who conducted real-life activities with a face mask during 4 hours. Panelists evaluated the stain of their face mask by visual assessment, while the makeup degradation on face was evaluated by color measurement by instrumental method. RESULTS: No difference was observed between the two products for lasting on face, but consumer evaluation showed a better resistance of product A for color transfer on mask. CONCLUSION: The mix of instrumental and consumer evaluation is a promising way to evaluate the makeup degradation on face and color transfer on mask, which are two key factors to develop mask resistant makeup products.