Autoimmune neuropathies such as the Guillain-Barré syndrome (GBS), the Miller Fisher syndrome (MFS), and chronic inflammatory demyelinating neuropathy (CIDP) have conventionally been considered diseases exclusively of the peripheral nervous system. In the last decades, however, several reports of CNS involvement in peripheral neuropathy have challenged this view. We describe a patient with anti-GQ1b positive MFS who--apart from the classical features--also presented with reversible loss of visual acuity suggesting CNS involvement.