The invention relates to a device of ocular iontophoresis for delivering active substances, comprising a reservoir having an outer wall and a hollow body at least partly delimited by the outer wall, wherein the hollow body is capable of receiving an electrical conductive medium and active substances contained in the medium and has an outlet defining a surface, so-called “application surface”, intended to receive a determine part of an eyeball surface, the application surface being at least partly limited by an outer line concave towards the optical axis of the eyeball, wherein the outer wall extends from the outer line with a global outwardly with respect to the said optical axis.