The present invention relates to an device comprising:- a first part (10) comprising a rim (12) having the shape of a circle or of an arc of a circle, said circle having an axis X and a radius of greater than 5 mm and of less than 8 mm, so as to substantially correspond to the radius of the limbus (L) of the eye (O),- a second part (30) mobile relative to the first part and guided by said first part, said second part comprising an invasive first electrode (40) and/or a second electrode (50) having a spherical electrode contact surface (52) born by a virtual sphere, the radius of curvature of said electrode contact surface ranging between 15 mm and 18 mm, and being preferably about 16.5 mm, so as to substantially correspond to the radius of curvature of the outside surface of said eye,the first and second electrodes being designed to be connected electrically to first and second terminals, respectively, of an electrical generator.
