The eye is a highly specialized system of the body that has been designed with mechanisms for its own defense, and these defense mechanisms create challenges in administration of medications to the eye. Therefore, ocular drug delivery has been a major challenge to drug delivery researchers. There are on-going studies, in search of treatments especially for diseases affecting the posterior segment of the eye. This book gives an overview of the background of ocular drug delivery and is unique for pharmacists, medical practitioners, health science students and drug delivery researchers.