Abstract
Pneumosinus dilatans is an abnormal expansion of the air-filled paranasal sinuses. Usually found incidentally on radiology, it does rarely present in the form of cosmetic, neurological, ocular or rhinological pathologies. We report a case of a young male with complaints of bilateral gradual vision loss, diagnosed as pneumosinus dilatans with optic nerve atrophy. He underwent bilateral optic nerve decompression. A review of all cases of pneumosinus dilatans, reported over the last 100 years in English literature is presented.