Three layers: - Fibrous tunic (outer layer) consists of sclera (white of the eye) and cornea (transparent part). - Uvea or vascular tunic (middle layer) consists of choroid (vascular layer), iris (colored part regulating pupil size) and ciliary body (changes lens shape and feeds cornea). - Retina (inner layer), the light-sensitive part. The pupil is not a structure, it is a hole with a variable diameter.