There is a recognized need for a staging classification system after diagnosis and before treatment of any type of cancer. The T (tumor), N (node), and M (metastasis) staging system relies mainly on the description of the anatomic extent of the tumor. The revised eighth edition of the American Joint Committee on Cancer (AJCC)/TNM staging classification can serve many purposes in providing a consistent global common language, standardized inclusion and stratification criteria for the study population, multicenter data sharing, and continuous updates from experts. In addition to being a strong indicator of prognosis, the AJCC/TNM classification is also an essential tool for cancer patients by its ability to predict response or resistance to local treatment and to compare outcome and survival rates from medical centers. In ophthalmic oncology, significant changes have been made in the staging classification over the last decades. The International Ophthalmic Oncology Task Force (OOTF) has contributed to improving and validating the AJCC/TNM staging classification for eye tumors, maintaining its clinical relevance and universal applicability. Further periodical updates are to be expected with the advent of new adjuvant therapy or prognostic factors, such as genetic features and molecular markers.