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.
Uniform light can be expressed through various bodies, selected according to the size of the bathroom. For a small bath uniform light can be obtained with the help of two bodies of lighting arranged on either side of the mirror, and for a large bath the light may be obtained by using a lightning body affixed to the ceiling, above huge mirrors.
Bathroom is also considered to be the most important room or living space in any home. Nowadays, bathroom is not just a place where people just have a quick wash and perform morning ablutions, but also a place where they groom themselves as well as wash away a day's tiredness and strain.