Eyelashes Eyelash Extensions is a practice that enhances the length, thickness and fullness to natural eyelashes. The extensions may consist of silk, mink, or synthetic hair. Methods of applying the extensions include full strips, clusters, and individual, one-by-one extensions. The use of Henna for body art is several centuries old at least. The people of ancient Egypt and India used this form of temporary tattoo for religious ceremonies, wedding festivals, and for simple body adornment.