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Skin
appearance and skin color
When we look at skin many factors affect what we actually see, including
the brightness and color of the light, the state of the skin and
the basic skin color. These all combine to produce an effect
that can alter dramatically.
In normal daylight, what we see is partly light
reflected from the surface of the stratum corneum and partly light
reflected back from the dermis through the translucent epidermis.
If the stratum corneum contains adequate moisture and the dead cells
(squames) have been removed,
it is more translucent and reflects light more evenly, giving
the skin a 'shine'.
Model of
the translucency of the skin.
If the skin is dry and covered in squames
it scatters light instead of reflecting it evenly, and looks dull.
(Much the same is true for hair.) If dry skin or hair is wetted
with water, or better still with oil, it looks glossier because
it reflects light better. This can be demonstrated very clearly
on dry leather.
This also explains why moisturizers and exfoliators
help skin to look healthier. They smooth down or remove the squames
and help the epidermis to retain its moisture, so reflecting light
better.
Changing
this light reflection is a crucial part of what cosmetic products
can do.
Very dark skins, with pigment throughout the epidermis, reflect
less light from the dermis. But in skins with little or no pigment
in the epidermis, the state of the tiny blood vessels in
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| Our
skin is not so very different from leather: stiff and dull
when dry, pliable and with a slight sheen when moist. |
the dermis and the state of the dermis itself play a greater part
in the 'complexion'.
What we see as the actual skin color, as distinct from
the condition, depends on light that is reflected by four
different colored components of the skin, which are found at different
levels throughout the epidermis and the dermis. These reflections
combine to give us our unique skin color. They are:
- melanin
in the epidermis
- red
blood cells containing oxygen in the small blood vessels
of the dermis
- red
blood cells without oxygen in the same blood vessels
- orange-yellow
chemicals called carotenoids
in the stratum corneum and the subcutaneous fat layer; these
are principally responsible for the yellow tones of skin
color, and are more abundant in men's skin than in women's.
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Carotenoids are found in carrots.
Eating too many carrots can turn you orange!
Of these four factors, melanin is the most important in deciding skin
color. The |
