Bathrooms are characterised, in general, as more restricted areas - they are not always the big, airey rooms we may hope for and, often, do not have natural light. As such, lighting becomes more important than usual. Lighting must be more intense than in the rest of our house, as compared with the needs of the room.
Generally, whenever one talks about lighting a bathroom, a wall mounted fixture above the mirror props up immediately in one's mind. Even though, this is the most common type of lighting fixture known to people since last century, there are wide varieties and styles of lighting fixtures that are now available in the markets all over the world.
They allow light to be evenly reflected across your face removing any shadows that may deceive you or make it hard for you to groom yourself properly in a timely fashion. Recessed lights are best for the shower stalls and areas over bathtubs and toilets.
There is no rule such that the bathroom lighting should be provided only in the ceiling or is better if it is provided at the sides or on top of the mirror. One has to fix the bathroom lightings according to one's taste and the mood that he or she wants to bring into the room. Even for a small bathroom, people, these days, go for two or more lighting fixtures. Thus, lighting is the most important factor to be considered in any modern bathrooms.