The uvea is an anatomical term used to describe three embryologically related structures in the eye: the iris, ciliary body, and the choroid. The iris is the colored part of the eye and serves as a muscle to control the size of your pupil. The ciliary body is a ring of muscle that sits behind the iris. The ciliary muscle changes the shape of the flexible lens and allows fine visual focusing. The choroid sits under the retina in the back of the eye. The choroid is a bed of blood vessels sitting under the retina that provides oxygen and nourishment to the photoreceptors. The term “uvea” is an anatomical description and is mainly useful in describing the condition uveitis. Uveitis is an inflammation of the uvea structures, and can involve inflammation of the iris, ciliary body, and/or choroid.