Visual disturbances in advanced cancer patients are very rarely signaled, evaluated, or adequately treated. The main causes of sight disturbances are primary eye tumors, ocular metastases, and some paraneoplastic syndromes. Sight alteration can also be associated with asthenia, fatigue, anemia, and hypovitaminosis. These symptoms can be monocular or binocular, and their gravity and evolution can vary. Based on a survey of 156 patients, we estimate the prevalence of visual disturbances to be 12% in advanced cancer patients.