The Skin protects us by acting as a barrier against bacteria, viruses, and other external elements. The melanin found in the skin acts as a filter to prevent skin damage from ultraviolet light. All individuals have the same number of melanocytes, the density of melanin produced in the skin is determined by evolution, migration, and genetics. The Fitzpatrick Scale is a numerical classification for different skin tones. The Fitzpatrick Scale measures the reaction to sun exposure, genetic disposition, and skin tanning.