The invention provides a device for a medical treatment of a sclera, the device comprising a single applicator connected to a shaft, wherein the applicator is configured to be placed into the Tenon's space； the applicator has a first surface, wherein the first surface of the applicator is superficially contactable to the surface of an area of the sclera so as to superficially cover said area； and the applicator comprises a single optical outlet connected to a single optical guiding element extending from a proximal end of the shaft to the single distal optical outlet at the first surface of the applicator, the optical guiding element being configured for guiding electromagnetic waves towards the optical outlet, wherein the optical guiding element is configured to guide electromagnetic waves of a wavelength adapted for thermal treatment of the sclera by protein coagulation.
