Book excerpt: Although noninvasive, continuous monitoring of glucose concentration in blood and tissues is one of the most challenging areas in medicine, a wide range of optical techniques has recently been designed to help develop robust noninvasive methods for glucose sensing. For the first time in book form, the Handbook of Optical Sensing of Glucose in Biological Fluids and Tissues analyzes trends in noninvasive optical glucose sensing and discusses its impact on tissue optical properties. This handbook presents methods that improve the accuracy in glucose prediction based on infrared absorption spectroscopy, recent studies on the influence of acute hyperglycemia on cerebral blood flow, and the correlation between diabetes and the thermo-optical response of human skin. It examines skin glucose monitoring by near-infrared spectroscopy (NIR), fluorescence-based glucose biosensors, and a photonic crystal contact lens sensor. The contributors also explore problems of polarimetric glucose sensing in transparent and turbid tissues as well as offer a high-resolution optical technique for noninvasive, continuous, and accurate blood glucose monitoring and glucose diffusion measurement. Written by world-renowned experts in biomedical optics and biophotonics, this book gives a complete, state-of-the-art treatise on the design and applications of noninvasive optical methods and instruments for glucose sensing.