Cosmetic treatment method for adding fibers to natural eyelashes, comprising: a) applying an adhesive composition (A) to at least part of the eyelashes, b) bringing fibers (12) borne by an applicator (10) into contact with said adhesive composition (A) present on said eyelashes, c) moving the applicator (10) away from the eyelashes, so as to release fibers (12) which adhere to said eyelashes.
