Eye doctors use specialized techniques and tools to detect abnormalities in the eye that may indicate the presence of cancer. During a comprehensive eye exam, the doctor will check various parts of the eye, including the retina, optic nerve, and blood vessels, for signs of tumors or other abnormalities. Techniques like fundus photography, optical coherence tomography (OCT), and fluorescein angiography can provide detailed images that help in diagnosing ocular cancers.