It's important to properly evaluate the vein before treatment. Without seeing a photo, it is difficult to assess, but bluish veins can be a venous lake, angioma, telangiectasia, as well as a dilated vein. If it has been present for years, a venous malformation is also possible. I would see a dermatologist who has experience in vascular lesions.
Treatment for these veins really depends on the size and depth of the blood vessels. Lasers are the best with the least amount of complication. I generally treat these veins with either Pulsed Dye Laser or KTP (for smaller vessels), or Nd:Yag for larger vessels. Bluishi vessels are usually larger caliber and respond best to Nd:Yag. You will have some temporary bruising to the area that last about one week. Several treatments may be necessary to completely remove the vessel.
While one can theorectically treat veins around the face with Sclerotherapy, I would seek someone with significant experience in sclerotherapy. The risk for serious complications including skin necrosis far outweighs the benefits, especially when there are much better alternatives. I use sclerotherapy frequently on spider veins of the legs but lasers are much more elegant and safer on the face.