Lumineers and veneers are very similar in that they are used to solve similar problems. They are both thin pieces of porcelain that cover the front of teeth in order to change the shape, size or color of the tooth. The difference is that Lumineers are known for the ability to place them without having to alter (or prep) the tooth before they are placed. Because of this they are usually much thinner than a classic veneer (which requires removal of some tooth). Due to the fact that they are thin, they can be weaker and have difficulty covering up some color problems. The classic veneer is usually thicker and therefore you have more porcelain to work with which makes it easier to get a more consistent uniform smile in the end. They both have their places and a properly trained cosmetic dentist will be able to let you know what is right for you.