As clients lie on a table with their eyes shut, a professional applies artificial lashes strand by strand, carefully bonding them about a millimeter away from the eyelid to avoid any contact with the skin or eye.

The look stays intact for about two to six weeks. Natural eyelashes have a finite lifespan, and when they fall out, they take the extensions with them.

Lash extensions generally come in two varieties: mink and synthetic. Mink extensions are made from sanitized, hypoallergenic hairs collected by brushing live mink, the same petite carnivores whose famously soft fur is prized for a variety of other applications.

For synthetic extensions, lab technicians replicate the look and feel of natural hairs by forging lashes from plastic, faux-mink poly fibers, silk blends, or high-quality keraspecific fibers, which are chemically identical to real human hair. No matter the material, extensions should feel comfortable and light as they frame what poets have long called “the windows to the soul.”