Fibers are expendable. Kind of like hair, they will fall out over time and at some point you'll have to replace them, but they'll last a long time.
If your fibers are snapping off, this can happen over time from normal use, and can be reduced and prevented with proper care and maintenance. Please be sure you are storing your FiberFlies in their handy cloth bag when not in use, and using personal silicone lubricant to keep the fibers from becoming brittle.
We recommend using silicone personal lubricant - the kind used for massage, sex, etc. as it is hypoallergenic, tested safe for human contact, and contains no solvents harmful to the acrylic optical fibers. The Swiss Navy brand silicone personal lube is among the best we've found for fibers and quite cheap in bulk on Amazon Prime. Pjur is also quite good! It will help keep the fibers sliding smooth on your skin.
*Be sure to use SILICONE, and not other types of personal lube; others will get sticky & gross quickly. Industrial solvent-based lubricant that has a silicone additive is NOT recommended by us. It can chemically compromise the acrylic.