While many types of institutions need to achieve effective visual communication, museums have a problem that is unique. The light that stimulates vision also causes permanent damage to many museum exhibits, and this includes most forms of art media. Preventive conservation is the discipline concerned with the processes that affect museum objects over time, and the museum professionals of that discipline have made important contributions to preserving our artistic heritage for future generations. This book aims to provide a basis for a similar level of professional expertise for lighting practice in museums. Rather than portraying conservation and display as having diametrically opposed objectives, the aim of this book is to lead all of the professionals concerned to consider how the overall viewing situation may be optimized for the nature of display that is envisaged, and for the lighting designer to devise a means for achieving this with minimal light exposure of the displayed objects.