Publisher Summary The “immune privileged” status of the eye is believed to be based on five different mechanisms including: (1) the blood-ocular barrier, (2) the absence of lympha tic drainage from the eye, (3) soluble factors with immune regulatory properties in ocular fluids, (4) the expression of immune regulatory molecules on the epithelial cells lining the interior of the eye, and (5) tolerance inducing antigen presenting cells (APC). This chapter describes some of these mechanisms. Avoiding intraocular infection and inflammation are of paramount importance to preserve the vision. Different strategies are employed to achieve this goal. Intraocular elimination of pathogens requires a fine balance of the immune system in strictly controlled manner to avoid permanent damage to the delicate structures of the eye. Experimental work during the last decades has disclosed a surprising complexity of regulation. These investigations have primarily focused on the anterior segment of the eye so far, but recent experiments have elucidated some of the strategies that have been used for the posterior segment of the eye.