Keratoconjunctivitis vernalis (VKC) and Atopic keratoconjunctivitis (AKC) are bilateral, recurrent disorders of the ocular surfaceOcular surface that can lead to severe corneaCornea alterations. Clinical characteristics are the formation of giant papillae in the tarsus region (diameter > 1 mm) and/or changes near the limbus (“trantas dots”). The etiology and pathophysiologyPathophysiology remain unclear. Clinical findings and immunohistological examinations suggest that complex (both IgE-dependent and IgE-independent immunopathological) changes are involved. Predisposing factors include endocrine, genetic, neurogenic as well as environmental and socioeconomic influences. Whereas VKC affects mostly childrenChild and often has a self-limiting course, onset of AKC is commonly later and runs a prolonged clinical course. Clinically VKC and AKC are very similar and there is controversy regarding classification of both disorders. It has been proposed that VKC is a childhood form of AKC that evolves into AKC in adulthood. Antihistamines, mast cell stabilizers and, if necessary, topical steroidsSteroid have proven effective as acute therapyTherapy. However, this treatmentTreatment approach is insufficient in severe cases and cannot completely avoid recurrence. Immunomodulators such as Ciclosporin A and tacrolimus are alternative agents, especially for long-term therapyTherapy. In AKC patients, vision-threatening complicationsComplications occur including transformation to malignancies.