Definition of primary intraocular lymphoma -- History of primary intraocular lymphoma (1950s-1970s) -- Classification of lymphomas -- Epidemiology of primary intraocular lymphoma -- Clinical manifestations of PIOL -- Imaging -- Pathology -- Immunology of PIOL -- Diagnostic approaches -- Management and treatment of PIOL -- Prognosis in PIOL -- Hypotheses on the origin of PIOL -- Experimental models of PIOL -- Summary and algorithm -- The future of PIOL -- Case illustrations.