Acanthamoeba infection is a more and more frequently occurring disorder all over the world and in Hungary as well. Beside diagnostic and therapeutic possibilities it may cause serious visual loss. The characteristics of the disease are summarized and presented. It mainly affects people wearing contact lenses with poor hygiene. The subjective signs of the disorder are pain, red eye, tearing and eyelid swelling. In the clinical appearance the ring-shaped ulcer invading the corneal stroma is typical. From differential diagnostic point of view bacterial, fungal, and herpes simplex infection should be excluded. In the diagnosis confocal corneal microscopy and specific laboratory tests are recommended. A wide range of conservative and surgical treatment options are available for treatment. However, early diagnosis and long-lasting adequate therapy are necessary for effective recovery. Prevention is the most important task of contact lens specialists, to inform the patients about adequate hygiene and up-to-date contact lenses and cleaning solutions.