Ten distinct eye designs have been identified in the animal kingdom. Whereas vertebrates possess only one, invertebrates possess all ten, from simple assemblies of photoreceptors to advanced compound and camera eyes, which support a sophisticated range of visual behaviours. Many invertebrates have exquisite sensitivity to light, can distinguish a broad spectrum of colours, detect subtle polarised light cues, and negotiate obstacles at high speed. The basic principles used to acquire and process such visual information are remarkably similar across the animal kingdom. In invertebrates, these principles frequently involve neural tricks and short cuts, some of which have been successfully exploited to create artificial visual systems for robots. Invertebrate Vision is a complete synthesis of our current knowledge concerning how invertebrates see, the principles used to process visual information and how vision is used in the daily struggle for survival. It will appeal to anyone interested in the vision sciences.