In anatomy, the<unk> (plural<unk> s or irides) is the most visible part of the eye of vertebrates, including humans. The following describes the<unk> of vertebrates, not the independently evolved<unk> found in some cephalopods.  The word comes from Greek mythology, in which<unk> is the anthropomorphized form of the rainbow.
The<unk> consists of pigmented fibrovascular tissue known as a stroma.  The stroma connects a sphincter muscle (sphincter pupillae), which contracts the pupil, and a set of dilator muscles (dilator pupillae) which open it. The back surface is covered by an epithelial layer two cells thick (the<unk> pigment epithelium), but the front surface has no epithelium.  The outer edge of the<unk>  known as the root, is attached to the sclera and the anterior ciliary body. The<unk> and ciliary body together are known as the anterior uvea.  Just in front of the root of the<unk> is the region through which the aqueous humour constantly drains out of the eye, with the result that diseases of the<unk> often have important effects on intraocular pressure, and indirectly on vision.
Iris 
Lacrimal bone
Earlobe
Canthus 
Aura 
Orbit 
Maxilla
Olea