Acanthamoeba keratitis has become a clinical problem together with the widespread use of soft and rigid contact lenses. The number of cases with this kind of infection is growing, but many of cases are diagnosed too late or misdiagnosed. The authors presented, for the first time in Polish literature, a case of acanthamoeba keratitis concerning a 62 aged man. The disease was diagnosed in the right aphakic eye after a 5-year use of soft contact lens, just after cataract operation performed in the clinic in the left eye.