As you would at the hairdressers before you have a full head of colour, you will be required to have a patch test before you have eyelash extensions. The patch test is nothing to worry about, but is important as it will determine whether you can go ahead with the treatment – ruling out any potential allergic reactions. Different lash artists will patch test in different ways. Here at The Eyelash Emporium we patch test by applying individual lashes to the outer lashes. All patch tests must be conducted 48 hours prior to your treatment.