In endovenous laser treatment, a thin fiber is inserted into the damaged vein through a very small entry point in the skin. A laser light is emitted through the fiber, as the fiber is pulled back through the vein, it delivers just the right amount of energy. The targeted tissue reacts with the light energy, causing the vein to close and seal shut. The veins that are closed are superficial veins that handle less than five percent of the body’s blood flow. The blood is automatically routed to other, healthy veins.