Wall Sconces serve more than one purpose in that they can accentuate something on the wall (for example a picture or a shelf) in the form of accent lighting, or they can create mood-lighting with a soft glow. In addition, they can provide functional task lighting around a mirror. Depending on the situation, Wall Sconces are a very useful part of the overall lighting scheme.
If you are looking for a wall sconce for your bedroom, to assist in late night reading, this qualifies as task lighting. I would suggest choosing a sconce that shines down to help better illuminate the space. An example of this type of sconce is featured below.