Hypereosinophilic syndrome (HES) is a rare disorder, in which eosinophilic toxins damage capillary and coronary endothelium and neuronal axons, at different target organs; 12% of patients experience stroke as a result of endothelial dysfunction, cardiomyopathy with secondary embolism, hyperviscosity and hypercoagulability. The treatment target is to lower the eosinophil count and shorten its tissue survival time. Supportive care and anticoagulants are given as required. We report a case of myocarditis, respiratory failure and cortical blindness due to rapidly deteriorating HES. The case demonstrates how early recognition and appropriate treatment can reduce tissue toxicity and functional loss due to hypereosinophilic syndrome.