Experimental animal models are the bedrock of modern biomedical research. They provide unparalleled insights into basic pathophysiological mechanisms of human diseases and have been invaluable in identifying, developing, and validating new drugs and treatment modalities. This truism is applicable to vision research as reflected by the chapters in this compendium on animal models of a wide variety of important ocular diseases including cataract, diabetic retinopathy, retinal degeneration, glaucoma, age-related macular degeneration (AMD) , as well as infectious and autoimmune ocular diseases. As aptly stated by West-Mays, Bowman, and Yizhi Liu in the chapter on animal models of primary and secondary cataracts , “elucidation of the mechanisms underlying cataractogenesis has only been possible through the use of experimental animal models.” Although a variety of rodents (mice, rats, and guinea pigs), mammals (rabbits, dogs, and primates), invertebrates (fruit flies and nematodes), and zebrafish models have been developed for the study of human ocular diseases, the mouse species is by far the most common. Mouse models have gained wide popularity in vision research because the mouse eye is structurally similar to the human eye, manifests many ocular disorders of humans, and has an accelerated life span that allows for investigations of the natural history and progression of eye diseases over relatively short time periods.