External aggressions and complexion radiance

Focus on complexion radiance
published on 18/03/2021

Blue light, pollution, smoking or UV .... The skin is exposed daily to many factors that can gradually cause oxidative stress in the skin cells ... which can then affect the complexion radiance!


External aggressions: their impact on the complexion radiance

With teleworking, semi-confinement, wearing masks ... consumers are more in search of care to protect their skin from daily aggressions. Indeed, exposure to blue light, UV rays or pollution generates free radicals in the skin, causing faster oxidation of cell membranes and altering the regeneration system of skin cells. These exposures cause damage to the skin, such as a duller, less even complexion and the appearance of blemishes.

Focus on blue light

With the health crisis, digital devices have become essential for individuals and are now an integral part of their lifestyle. Indeed, according to a study by Unilever, 60% of people now spend more than six hours a day in front of a screen. However, it is important to note that the blue light emanating from digital devices is harmful for the skin cell renewal. Unilever has shown that five days of work can have the same impact on the skin as spending 25 minutes exposed to the sun in the middle of the afternoon without any protection. Result: the skin loses its radiance!


Complexion radiance: a multi-faceted challenge

The skin of the face is the first thing visible on any individual. It is also one of the only visible parts of the human body. Therefore, consumers are seeking a "healthy glow" effect through the use of cosmetic products to reduce the inconveniences caused by external aggressions. However, for cosmetic brands, the complexion radiance can be a difficult aspect to objectify, knowing that it reflects well-being...

Indeed, the skin of the face can provide a lot of information at first glance, such as the age perception or health status of the person, since a radiant complexion is usually considered as a sign of good health and youth.

The parameters of complexion radiance

The complexion radiance depends on the light interaction with the skin. Several parameters contribute to this radiance:

  • Skin colour, determined by chromophores (melanins, hemoglobins and carotenoids) and influenced by skin microcirculation;
  • Light reflection;
  • Texture of the skin or its microrelief;
  • Transparency of the skin.

Thanks to these different parameters, and in order to meet consumers' expectations, research work has been carried out to analyze the complexion radiance and to propose cosmetics that can act on the skin's ability to reflect light.


Complexion radiance, claims and test protocol

Many claims are now associated with complexion radiance:

  • "Improves the complexion radiance"
  • "Provides a healthy glow".
  • "Provides a clearer complexion" (lightening effect)
  • "Evens out/homogenizes the complexion
  • "Corrects irregularities of the complexion"
  • "Brings a fresh and luminous complexion"
  • "Improves the appearance of the skin”
  • ...

In 2004, in response to these types of requests, Spincontrol Group, in collaboration with L'Oréal Paris, developed a method for clinically measuring skin tone: the CLBT® method.

CLBT®: a visual and sensory assessment model for complexion radiance

The CLBT® method, a skin tone assessment method, is based on a sensory and visual analysis of four descriptors, performed by qualified assessors:

  • Skin color (C), defined by the evaluation of the four shades characterizing Caucasian skin: pink red, beige, olive, light pink. Each of these shades is broken down into percentages of saturation, in order to establish a color chart;

  • Luminosity (L), qualified by the intensity of the luminous spots on the prominent areas of the face;
  • The brightness (B), resulting from the uniformity of the skin color and the regularity of the skin texture (the homogeneity of the skin);
  • Transparency (T), representing the possibility of seeing the veins under the skin.

The evaluation of the colours is carried out using calibrated pantones, while the other descriptors are evaluated using analogical scales.

Reliable and reproducible, the CLBT® method thus makes it possible to evaluate descriptors, thanks to the capacity of human senses to integrate multifactorial parameters, and therefore to prove a very specific and difficult-to-objectify statement which is the complexion radiance.


In conclusion, complexion radiance is a fascinating but also complex claim to apprehend, which arouses a strong interest from consumers, in order to fight against daily aggressions. Our team is therefore at your disposal to help you evaluate the effectiveness of your products, intended to improve the “complexion radiance”.

For more information, contact our team



Musnier C, Piquemal P, Beau P, Pittet JC (2004). Visual evaluation in vivo of complexion radiance using the CLBT sensory methodology. Skin Res Technol, 10 : 50-55