In 101 eyes with either anterior or retrobulbar optic neuropathy of ischemic or inflammatory origin, ocular pain occurred significantly more often with retrobulbar optic neuropathy. The association of pain with posterior optic nerve lesions supports Whitnall's hypothesis that the pain of optic nerve inflammation is caused by traction of the origins of the superior and medial recti on the optic nerve sheath at the orbital apex. Eye pain reflected neither severity nor origin of optic neuropathy.