The ERMION consortium involves four research teams from France (D Bonneau, Angers; G Lenaers, Montpellier), Germany (B Wissinger, Tûbigen) and Italy (A Martinuzzi, Conegliano), and focuses on inherited optic neuropathies one of the most frequent causes of hereditary vision loss. Optic neuropathies have an estimated prevalence of 1:10.000 and affect more than 50.000 persons in Europe. In 2000, two ERMION partners identified the gene OPA1 as the major gene responsible for autosomal dominant optic atrophy, the most frequent form of optic neuropathies. ERMION partners work together since 2003 to understand the pathophysiology of optic neuropathies and, more particularly, the pathomechanisms involved in OPA1 related disorders. This collaboration resulted in the publication of 9 per-reviewed research articles (total impact factor: 63). The mutual objectives of the ERMION partners are now : i) To have a strategy for developing common projects in the field of optic neuropathies, ii) To share expertise , iii) To promote new experimental approaches to the study of optic neuropathies, iv) To promote innovative therapeutic strategies and future clinical trials at the European level, v) To promote researcher exchanges between the different labs and vi) To maintain and reinforce the visibility of our European network