Traditional adaptations of tropical/sub tropical buildings to high ambient irradiance from high elevations are outlined. Generally, these adaptations result in severe shading of window apertures, greatly reducing access to daylight, Some examples of optical systems designed to improve daylighting in tropical buildings are discussed. These include angle selective glazing. light guiding shades, vertical and horizontal light pipes, switchable glazing and angle selective skylights. The simulation of these devices within packages such as RADIANCE is also discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.