The choroid coat, or simply choroid, is a part of the eye that is located between the retina and the sclera. It is a vascular layer that supplies oxygen and nutrients to the retina. The word "choroid coat" has a few synonyms, such as choroid membrane, uvea, or vascular tunic. The choroid membrane is made up of blood vessels, connective tissue, and pigment cells. It also contains melanocytes, which produce melanin, the pigment that gives the eye its color. The uvea is a Latin term that refers to the entire vascular layer of the eye, which includes the choroid, iris, and ciliary body. The choroid coat is a crucial part of the eye that helps support and maintain the health of the retina.