This chapter opens with description of basic morphology of fungus, its classification and the body’s defence against it. Fungus can attack any part of the eye and its adnexa. Keratomycosis incidence has increased of late due to certain reasons and the types of fungus have multiplied. Knowledge of the clinical features is very important in suspecting a case as that of fungus. The important signs and symptoms are discussed. The diagnosis is based on the clinical features and lab study. The features also differ between various fungi. The treatment is mainly by antifungal drugs (classified) and avoiding certain drugs. The antifungal drugs are discussed in detail. So also the other ancillary drugs given for this condition. Surgical treatment is usually not the initial resort. Many points are explained with photos.