Light skinLight skin is a human skin color that has a base level of eumelanin pigmentation that has adapted to environments of low UV radiation. Light skin is most commonly found amongst the native populations of Europe and Northeast Asia as measured through skin reflectance. People with light skin pigmentation are often referred to as "white" although these usages can be ambiguous in some countries where they are used to refer specifically to certain ethnic groups or populations.
SunglassesSunglasses or sun glasses (informally called shades or sunnies; more names below) are a form of protective eyewear designed primarily to prevent bright sunlight and high-energy visible light from damaging or discomforting the eyes. They can sometimes also function as a visual aid, as variously termed spectacles or glasses exist, featuring lenses that are colored, polarized or darkened. In the early 20th century, they were also known as sun cheaters (cheaters then being an American slang term for glasses).
PsoralenPsoralen (also called psoralene) is the parent compound in a family of naturally occurring organic compounds known as the linear furanocoumarins. It is structurally related to coumarin by the addition of a fused furan ring, and may be considered as a derivative of umbelliferone. Psoralen occurs naturally in the seeds of Psoralea corylifolia, as well as in the common fig, celery, parsley, West Indian satinwood, and in all citrus fruits.
Dark skinDark skin is a type of human skin color that is rich in melanin pigments. People with very dark skin are often referred to as "black people", although this usage can be ambiguous in some countries where it is also used to specifically refer to different ethnic groups or populations. The evolution of dark skin is believed to have begun around 1.2 million years ago, in light-skinned early hominid species after they moved from the equatorial rainforest to the sunny savannas.
ErythemaErythema (from Greek 'red') is redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries. It occurs with any skin injury, infection, or inflammation. Examples of erythema not associated with pathology include nervous blushes.
Tanning lampTanning lamps (sometimes called tanning bulbs in the United States or tanning tubes in Europe) are the part of a tanning bed, booth or other tanning device which produces ultraviolet light used for indoor tanning. There are hundreds of different kinds of tanning lamps most of which can be classified in two basic groups: low pressure and high pressure. Within the industry, it is common to call high-pressure units "bulbs" and low-pressure units "lamps", although there are many exceptions and not everyone follows this example.
Pyrimidine dimerPyrimidine dimers are molecular lesions formed from thymine or cytosine bases in DNA via photochemical reactions, commonly associated with direct DNA damage. Ultraviolet light (UV; particularly UVC) induces the formation of covalent linkages between consecutive bases along the nucleotide chain in the vicinity of their carbon–carbon double bonds. The photo-coupled dimers are fluorescent. The dimerization reaction can also occur among pyrimidine bases in dsRNA (double-stranded RNA)—uracil or cytosine.
SunscreenSunscreen, also known as sunblock or sun cream, is a photoprotective topical product for the skin that helps protect against sunburn and most importantly prevent skin cancer. Sunscreens come as lotions, sprays, gels, foams (such as an expanded foam lotion or whipped lotion ), sticks, powders and other topical products. Sunscreens are common supplements to clothing, particularly sunglasses, sunhats and special sun protective clothing, and other forms of photoprotection (such as umbrellas).
Basal-cell carcinomaBasal-cell carcinoma (BCC), also known as basal-cell cancer, is the most common type of skin cancer. It often appears as a painless raised area of skin, which may be shiny with small blood vessels running over it. It may also present as a raised area with ulceration. Basal-cell cancer grows slowly and can damage the tissue around it, but it is unlikely to spread to distant areas or result in death. Risk factors include exposure to ultraviolet light, having lighter skin, radiation therapy, long-term exposure to arsenic and poor immune-system function.
MoisturizerA moisturizer, or emollient, is a cosmetic preparation used for protecting, moisturizing, and lubricating the skin. These functions are normally performed by sebum produced by healthy skin. The word "emollient" is derived from the Latin verb mollire, to soften. In the human body, water constantly evaporates from the deeper layers of the skin through an effect known as transepidermal water loss (TEWL). By regulating its water content, human skin naturally maintains a dry, easily shed surface as a barrier against pathogens, dirt, or damage, while protecting itself from drying out and becoming brittle and rigid.
