The eye can become involved in immune-mediated diseases that affect it alone or as part of a multi-organ disease process. Much immunological attention has been focused on other organs affected by these processes and the subject of the immunology of eye diseases is a relatively new one. Many of these diseases that involve the eye are not life-threatening but can result in devastat­ ing loss of sight that if bilateral, will have major effects on the patient's life. Systemic immunological investigations are generally unhelpful in these patients and one of the major problems in this field has been the lack of diseased tissue available for examination to determine the pathological processes involved. Our poor understanding of basic mechanisms of disease in the eye has meant that treatment of many of these conditions is often inadequate. It has become possible to apply in the eye many of the techniques used to investigate the role of the immune system in other systems. Animal models of many of the disease processes have also allowed dissection of the immune response both within and outside the eye. It is my belief that a greater understanding of the mechanisms by which the structures in the eye become damaged will allow more specific and effective therapeutic strategies to be devised.