A 54 year old male presented with decreased vision and pain in his right eye His best or rected visualc smly was 0.6 in the right eye and 1.0 in the left eye. He had Onteal opasity cxophchalmus and mild optic disc cedeain in the right eye and normal findings in the tell -ev Right eye lovemnents were restlacted about I in lateral gaze and 2 in vertical gaze There eas a concentric defecl in the right visual field and a lesion surrounding the proximal 2M pan of the right optic nerve in orbital MR. Although optic nerve sheath meningloma is generally chRneTized by unpainful visual loss and exophillLLs in niddlk-ogcd woman, it should b serched in every case presenting with progressive unilateral visual loss.