If done properly, there will be no damage to your natural lash. If you pick and pull them out before they shed on their own, there will be damage. If a stylist places lashes that are too long or too thick for your natural lash, this can also cause damage, known as 'traction alopecia'. Please research any lash extension professional you are considering, to ensure they are properly trained, have experience, and are credible before you invest your money into your delicate eye area!