In the present study the clinical picture, therapy and pathogenesis of 6 retinal diseases are individually described and discussed. These are: familial tortuosity of the small retinal arteries, arteriovenous haemangioma, cavernous haemangioma, Leber's multiple retinal aneurysms, Coats' disease and von Hippel's haemangiomatosis retinae. They can all be subsumed under the broad concept of haemangioma and represent hamartias and hamartomas of the retinal vascular system.