Dermatological vascular laser (single wavelength) or intense pulsed light (broad spectrum) machines offer one of the treatments for rosacea, in particular the erythema (redness) of the skin.  They use light to penetrate the epidermis to target the capillaries in the dermis layer of the skin. The light is absorbed by oxy hemoglobin , which heats up, causing the capillary walls to heat up to 70 °C (158 °F), damaging them, and causing them to be absorbed by the body's natural defense mechanism. With a sufficient number of treatments, this method may even eliminate the redness altogether, though additional periodic treatments will likely be necessary to remove newly formed capillaries. 
Joshua A Zeichner, MD Assistant Professor, Director of Cosmetic and Clinical Research, Mount Sinai School of Medicine; Chief of Dermatology, Institute for Family Health at North General
Joshua A Zeichner, MD is a member of the following medical societies: American Academy of Dermatology , National Psoriasis Foundation
Disclosure: Received consulting fee from Valeant for consulting; Received grant/research funds from Medicis for other; Received consulting fee from Galderma for consulting; Received consulting fee from Promius for consulting; Received consulting fee from Pharmaderm for consulting; Received consulting fee from Onset for consulting.