The occlusion of the retinal artery usually leads to sudden and, in most cases, continual visual impairment of the affected eye. This is an uncommon illness with a variable progression. To date it has not been possible to develop a generally recommended therapy using prospective, randomised studies, as is the case for circulatory impairment in other organs. Due to this uncertainty, the treatment of a retinal arterial occlusion is regarded as an ophthalmological emergency and a challenge for the attending practitioner. In this overview, the actual state of our knowledge on the pathogenesis of occlusion of a retinal artery as well as current and new therapies are presented.