Application of transparent polymers in the consumer and precise optics depend on the knowledge of their optical and material characteristics. The book presents different refractive index measuring techniques in the visible and near-infrared spectrum. Principal, many trade-marks, and development optical grade polymers are considered. Extensive refractometric data of bulk samples, polymer solutions and thin films is reported. Metrological analysis of the experimental results is carried out. Computer modeling of normal dispersion is realized by our program Opticolor to calculate dispersion coefficients, curves, refractive indices and Abbe numbers. Influence of temperature is analysed. Original results on investigation of transmission, refraction and dispersion of optical polymers are presented. Some additional material characteristics are reported to facilitate the design of all-plastic or hybrid glass-plastic optics.