Over the last decade, polarised light and its use in nature has grown to take on a prominent role in visual neuroscience. This book covers many of the advances made since the 2004 Springer volume "Polarised Light in Animal Vision" edited by Horvath and Varju, but also provides reviews and synopses of some areas. With each chapter written by experts in the relavant field, the book is intended for anyone interested in animal vision, environmental optics, polarized light and polarization sensitivity. The book is divided into three sections. Part I examines polarization sensitivity across many animal taxa including vertebrates and invertebrates and details both terrestrial and aquatic life. Part II is devoted to the description of polarized light in nature and points towards how the physics of the light variables must be detected by the visual systems. This includes underwater polarization due to scattering; polarization patterns reflected from freshwater bodies; polarization characteristics of forest canopies; normal and anomalous polarization patterns of the skies; skylight polarization transmitted through Snel's window and both linearly and circularly polarized signals produced by terrestrial and aquatic animals. A large part of the book also examines polarized "light pollution" induced by anthropogenic factors such as reflection off asphalt surfaces, glass panes, car bodies, and other man-made structures that are now known to form ecological traps for polarotactic insects. Part III surveys some of the practical applications of polarization vision including polarization-based traps for biting insects, ground-based polarimetric cloud detectors and an historical examination of the navigational abilities of Viking seafairers using the sky polarisation compass. The deterrant qualities of ungulate pelage to polarization sensitive biting insects is also examined in this section.