Aim: To analyze the pathogenesis, clinical features, and treatment algorithm of fungal corneal ulcer with endophthalmitis to increase medical alertness and reduce the unjustified use of antibacterial and corticosteroid therapy in corneal diseases of various etiologies, leading to the development of secondary ophthalmomycosis. Results: The pathogenesis was analyzed, and the characteristic clinical symptoms of severe fungal corneal ulcer and endophthalmitis caused by Candida albicans were described. Intensive, long-term, unjustified antibacterial and corticosteroid therapy caused a prolonged course of herpetic corneal ulcer, as well as the addition of a secondary bacterial infection, and led to the development of severe corneal ulcer and fungal endophthalmitis in a 13-year-old child. Conclusion: The required maximum medical alertness and early, accurate clinical differential diagnosis between bacterial and fungal corneal ulcer, as well as the rapid flow of ophthalmomycosis and false-negative results of sowing content conjunctival sac entail expansion of the range and quantity of antibacterial drugs used in the absence of positive dynamics of antibiotic therapy and an increased frequency of secondary fungal infection. The clinical symptoms of a severe fungal corneal ulcer with endophthalmitis described in this report contribute to the early diagnosis of ophthalmomycosis before the type of pathogen is identified by laboratory methods, which makes it possible to start antifungal therapy earlier and avoid corneal perforation and eye loss. In most countries, due to the lack of an ocular form of antifungal drugs, for local treatment of corneal candidiasis, a 0.2% solution of fluconazole intended for intravenous administration is installed in the eyes.