The ciliary artery is a major blood vessel that supplies blood to the ciliary body and the iris. Synonyms for this term include the long posterior ciliary artery, LPCA, and the short posterior ciliary artery, SPCA. The LPCA arises from the ophthalmic artery and supplies the anterior and middle choroid layers, while the SPCA originates from the ophthalmic artery or the internal carotid artery and supplies the posterior choroid and optic nerve head. Another synonym for the ciliary artery is the vas ciliaris, which is a Latin term that describes its function. The vas ciliaris plays a crucial role in maintaining ocular health, and its dysfunction can lead to various eye diseases.