Corneal infection manifested as corneal fungal moss or ulcers, subcutaneous tissue type dark filamentous mycosis can be seen in the subcutaneous tissue with thin pus, cysts with exudate, if the cyst wall excision is incomplete, leaving a sinus tract, can not heal for a long time. Dark filamentous mycosis is a group of dark fungi caused by the tissue with dark mycelium as a characteristic of the skin, subcutaneous tissue or systemic infection. 1974 Ajello proposed this name. There are scattered cases of dark mycosis reported around the world, but it is mostly seen in the tropics. What causes corneas to have fungal moss or ulcers? (A) Pathogenesis Corneal fungal moss or ulcer is a cutaneous, subcutaneous or systemic infection caused by dark fungal infection characterized by dark mycelium in the tissue. (B) Pathogenesis The pathogenic routes are mainly exogenous and conditionally pathogenic infections. The route of infection is less clear and may be caused by implantation of the pathogenic fungus through the broken skin or inhalation of fungal spores. In recent years, disseminated cases have been reported in Shandong, northeast China and Zhanjiang. The pathogenic route is mainly exogenous infection and conditional pathogenic infection. The route of infection may be the implantation of the pathogenic fungus through the broken skin or inhalation of fungal spores. Clinical manifestations are superficial ulcers, petechiae, brownish-black spots, or warty growths, with minimal or mild itching or swelling, and some may be asymptomatic. Diagnosis relies on mycological examination and histopathological examination. Most of them are not sensitive to antifungal drugs and have poor efficacy. Patients tend to work outdoors and have frequent contact with such putrefactive materials. They may present as superficial ulcers, petechiae, brownish-black spots, or warty growths, and may be slightly itchy or mildly distended, or may have no conscious symptoms. Subcutaneous tissue type dark filariasis often has isolated, deep in the subcutaneous or muscle abscesses or cysts, lesions can be apricot kernel size or several centimeters, or even the entire chest large plaques. Systemic dark filariasis this type can be caused by the skin or subcutaneous tissue dark filariasis spread to the lymph nodes, lungs, brain and gallbladder, etc., but also no skin damage, the first lymph node or blood dissemination.