The eye, one of the initial exposure interfaces for allergens, is a common site for allergic disorders. Symptoms can range from mild eye itching to chronic cataracts and blindness. These disorders are differentiated by their clinical presentation as well as by the nature of immunological changes occuring in the conjunctival surface. Ocular allergic inflammation is typically associated with IgE-mediated mast cell activation. Mast cell-derived mediators (eg histamine, proteases, leukotrienes, and cytokines) initiate a cascade of events that culminate in the infiltration and migration of inflammatory leukocytes (neutrophils, eosinophils, and lymphocytes) to the ocular tissue. This trafficking of inflammatory cells requires attraction of these cells initiated by chemokines, and directed migration of the inflammatory cells out the bloodstream to the surface epithelium using adhesion molecules and their receptors.