The immune system is governed by dynamic events involving in part direct intercellular interactions between an immune cell and other cells or the cell's environment. Owing to its unique optical characteristics, the eye offers remarkable opportunities for the analysis of the immune system by intravital microscopy. In this review, we present a brief overview of the current state of knowledge of leukocyte trafficking in each of three anatomically distinct and medically important regions of the eye (cornea, iris, retina) as determined by the application of intravital microscopy to animal models of disease. Additionally, we discuss the use of ocular imaging in patients and volunteers. Finally, we examine the future prospects for this field in terms of its potential for impacting our understanding of fundamental immunological phenomena.