When applied properly eyelash extensions do not hurt. Extensions are applied to natural lashes, never touching the skin, so you shouldn’t feel anything. With your eyes closed, you may even find the treatment so relaxing that you fall asleep! In fact alot of Lash it up clients do! Note if it is your first time always ask for a patch test, some people are allergic to the glue and a patch test will identify this in a safe manner before you pay and have your lashes done.