Ocular histiocytosis is a rare and heterogeneous group of disorders which can occur in children and adults. There is a great challenge in the diagnosis and treatment because of the atypical clinical and imaging manifestations. With insights into molecular mechanism of histiocytosis, the discovery of BRAF^V600E mutations has changed the understanding of this disease and enabled targeted therapies in most patients. The gold standard of diagnosis has developed into histopathological biopsy combined with the testing for mutations. Surgery is not the only treatment for ocular histiocytosis and targeted therapy has become an effective treatment for patients with mutations in MAPK-ERK signal-regulated kinase pathway. However, the greatest challenge for ocular histiocytosis is establishing the early and correct diagnosis due to the diverse types and clinical manifestations. Therefore, this article reviews recent progress in diagnosing and treating ocular histiocytosis, summarizes their clinical and pathological features, and aims to improve the level of diagnosis and treatment among clinicians.