comparison of normal and melasma skin on woman face on white background.

melasma skin melanin pigment layer spot melanocyte melanogenesis blemish cell dark spots face damage epidermis dermis photoaging woman hyperpigmentation freckles pigmentation inflammation uva uvb rays premature cartoon aesthetic ultraviolet sunscreen prematurely ages dullness normal vector flat design diagram infographic healthy unhealthy dermatology cosmetology aging beauty comparison care facial tissue problem