I see many people who have tried laser treatments for their leg spider veins with no visible improvement. The reason for this is that spider veins need to be injected with sclerosing agents first before laser has any effect. Injecting the vein with an irritant such as hyper-tonic saline will cause the vein to collapse thus removing 80% of the color which is due to the blood inside the vein. The remaining visible color is now only in the vein wall which then can be treated with laser. If the vein is open and full of blood the amount of energy needed to collapse the vessel and remove the color would damage the overlying skin. No external laser can perform this safely. The safest and easiest method is to treat the vein with a safe sclerosing agent that will collapse the vein and do no further damage to the surrounding tissue; then laser the remaining color. Most people are happy with the injection alone, but certainly laser does improve the results even more.