Eye Components: 1) Fibrous Tunic - Holds the eye in place with anchoring muscle and provides protections. Contains sclera (external muscle that moves the eyeball, gives shape to the eye) & the Cornea (transparent, allows light onto retina) 2) Vascular Tunic - Nourishes the eye with blood supply. Contains the Choroid (black in color & absorbs light; is continuous with ciliary body which is an intrinsic muscle that changes the shape of the lens). 3) Neural/Inner - Contains the retina which has photoreceptor axons converging to form the optic nerve. 4) Rods - most numerous, allow you to see black and white. 5) Cones - fewer, allow you to see color. 6) Lens - focuses light on retina just like the cornea. 7) Iris - sphincter muscles to dilate and constrict pupil. 8) Optic Disc - Blind spot of retina, this is where the axons converge to create optic nerve. 9) Macula Lutea - Opposite of the pupil, precise posterior pole. 10) Fovea Centralis - Part of the Macula Lutea with the clearest vision. 11) Vitreous Humor - Clear substance that fills the posterior segment that transmits light and maintains normal pressure. 12) Aqueous Humor - Substance that fills both the anterior and posterior chamber of the anterior segment; nourishes the lens & cornea and helps maintain pressure.