An ophthalmological device for the treatment of keratoconus includes a cylindrical reservoir made of a non-conductive material, open at the top and bottom, and formed by two telescopically engaged portions, a lower one open at the bottom and connected to a cylindrical chamber of smaller diameter, also open at the bottom and formed by an external annular chamber that is concentrically arranged around the chamber and is closed at the top, open at the bottom, and adapted to be placed on the eye a first metallic conductor, housed in the container and connected to a terminal of a DC voltage generator, to the other terminal of which a second metallic conductor is connected a first conduit provided with a closing device, one end of the first conduit flowing into the annular reservoir, the other end being located externally thereto, whereby vacuum may be applied through the first conduit and a second conduit provided with a closing device, one end of the second conduit passing through the annular reservoir at its lower edge and flowing into the container, the other end being located externally to the annular reservoir. During irradiation, a hydrating solution is administered from above through the metallic conductor that touches the eye and is released through the conduit to avoid the excessive absorption of incident energy by the hydrating solution while maintaining a minimum thickness and constant hydrating solution on the ocular surface.