Patterns of light interference produced by damaged cuticle cells in human hair

Colorful patterns of light interference have been observed to occur in human hair Cuticle cells. The light interference phenomenon has been analyzed by optical microscopy. The strong patterns of light interference appeared only in Cuticle Cells that had been damaged either mechanically or by thermal stresses. Cuticle cells that were not damaged did not produce this phenomenon. The zones of light interference on the hair surface were seen to extend to Cuticle sheath areas whose damage was not apparent when analyzed under the Scanning Electron Microscope. The presence of oils and other hydrophobic materials in the hair had a strong effect in the appearance or disappearance of the interference patterns. Furthermore, the gradual absorption and desorption of water by the cuticle cells altered the nominal area of the colorful patterns. This paper will attempt to explain the light interference phenomenon in the cuticle cells by means of the two following mechanisms: 1) Variation in the index of refraction Of Cuticle Cell layers due to the appearance and coalescence of micro-voids which eventually lead to the partial or total separation of cuticle cells; and 2) The interaction of white light with the micro-voids and de-cemented cuticle cells either by thin film interference or diffraction.