Damaged human hair, bleached and straightened, SEM

False-coloured scanning electron micrograph showing the surface of a single strand of hair which has been heavily bleached and straightened. This image shows the tip of a hair taken from the front of the head of a female of Caucasian descent. Although naturally curly, the hair has been repeatedly straightened. Exposure to hair colour or dye, heating and drying can over time damage the hair shaft (barbed wire-like appearance seen here) making the hair brittle and more prone to breakage. The hair shaft is made up of several layers of a tough protein called keratin. The outer layer (cuticle) is visible here and is made up of overlapping, tightly packed scales. Horizontal width of image is 829 micrometres.