Principle of laser treatment of pigmented lesions: Laser treatment of pigmented lesions is based on the principle of selective photothermolysis, i.e., laser energy is absorbed by pigment particles (melanin vesicles, tattoo ink) in lesions in a very short period of time (10ns), generating a very high temperature (300°C), which causes them to expand rapidly and form microbursts, generating vaporization and crushing into very small particles, which are then phagocytosed and cleared away by macrophages within the tissues. Macrophages phagocytosis, removal. Laser treatment of pigmented lesions is only mildly painful: the treatment produces a sensation like a rubber band flicking the skin, generally without anesthesia. Sensitive areas (such as around the eyes), large areas and infants and young children can be treated with local infiltration anesthesia, surface anesthesia or general anesthesia, as appropriate. Laser treatment of pigmented lesions will not cause irreversible damage to the organism: the laser produces no damage or only slight reversible damage to the normal tissues of the human body, while irreversible damage is produced to the diseased tissues, showing a high degree of selectivity, and scarring will not be formed in general. The depth of penetration of the laser is limited, generally only reaching the dermis, and will not cause damage to the deeper tissues. As long as you avoid looking directly at the laser beam, there will be no effect on your vision, and your doctor will take certain measures to ensure that nothing goes wrong when treating around the eyes. Lasers are not rays and do not cause radiation damage to the body. Even for sensitive skin, allergic reactions to laser light are rare. After laser eyebrow tattoo and eyeliner removal, you can still grow normal eyebrows and eyelashes.