The case report describes the case of a 33-year-old man in whom acute corneal hydrops was the first manifestation of undiagnosed Norrie's disease. The patient had bilateral keratoconus, spherophakia and fibrovascular masses in the vitreous. Genetic testing revealed a new mutation in the NDP gene (c.140144delinsTTTTA; p.Ser47Ile48delinsPheLeu). The patient's mother was a carrier of this mutation. This mutation affects the function of the Norrin protein. This is the first case of Norrie's disease, which manifested as acute keratoconus in an adult. The findings highlight the importance of genetic testing for complex eye abnormalities.