Eyelash extensions are semi-permanent fibers that are glued to your natural lashes to make them appear longer, thicker and darker. The goal of lash extensions is to give the eyes a made-up appearance without the use of mascara or other eye makeup. While false eyelashes can also achieve this look, there are some key differences between false lashes and eyelash extensions. False eyelashes usually come in strips that you glue across the top of the natural lash line and remove at the end of the day. Eyelash extensions are individual fibers that are attached to each natural lash, one at a time. Once applied, eyelash extensions should last the average lifespan of natural eyelashes, which ranges from six weeks to two months.