The rare case of an 18-year-old man with a kind of convergence-evoked nystagmus was presented. His first symptom was vertigo, which was not accompanied by tinnitus or hearing loss. Two months later, he began to suffer from spells of dizziness lasting about 10 minutes which occurred when he walked or moved his head. His hearing was normal but his closed eye stabilometry indicated that he had disturbance in his equilibrium. He had pendular nystagmus which was evoked during convergence and when eyes were open in the dark. He had no gaze or head positional nystagmus. He had normal caloric response when eyes were closed. He also had smooth eye movement in eye tracking test and normal in OKN. His head CT and MRI results were normal. He had no other physiological, neurological or ophthalmological disease. His abnormal eye movement was thought to be the convergence-evoked pendular nystagmus, of which eight cases have been reported in the world. NIH image was very useful software to analyze to nystagmus. It may occur the results of disease in the central nerves. Therefore, follow-ups over 5 to 10 year periods are important.
