This Presentation is based on CIE Publication 157:2004 which has been recently published. It is the report of CIE Technical Committee 3-22 with the same title. Leading experts on Museum lighting from Australia, Canada, Finland, France, Japan, Germany, Great Britain, New Zealand and the USA, took part in writing this document. The two processes by which exposure to light may cause damage are photochemical action and radiant heating effect. These processes are examined and the characteristics of damage caused to museum objects are described. Recent research, which has aimed to relate the extent of exposure of materials to measures of damage is reviewed. It is concluded that all materials that are even slightly sensitive to exposure should be protected from ultra violet (UV) radiation, and two practical levels for control of exposure are proposed. The more critical, and more complicated issue is the control of damage caused by exposure to visible light. A four category classification of materials is proposed. These sensitivity classifications are related to ISO Blue Wool categories to provide a basis for objective classification of museum objects. A table is given which lists recommended limiting illuminances (lux) and limiting exposures (lux.hour/year) For each of the material sensitivity classifications a procedure for control is proposed. Specific tasks are listed to be carried out when setting up lighting for a new display, and during the life of the display. This procedure provides practical guidance for ensuring that the exposure of museum objects to UV, visible light and IR, is appropriately related to both needs for effective visual display and the control of damage due to exposure to light.