Have 3 tunics, 2 humors, and secretions. You can only see 1/6th of the eye, the rest is covered by fat and bones. 70% of all sensory receptors are located in the eye.
Lacrima
(S) secrete saline solution through canals (nasolacrimal duct --> nasal cavity) *contains antibodies & lysozyme
Conjunctiva
(S) covers outer surface of eye; secretes mucus
Conjuctivitis
pinkeye
Ciliary
(S) modified sweat glands between eyelashes (watery)
Meibomian
(S) sebaceous glands on eyelid edges (oily)
Aqueous
(H) anterior to the lens; clear, watery
Glaucoma
blocked drainage of aqueous humor; increased pressure --> pain, blindness; symptoms (slow to show) arehalos, headaches, and blurry vision
Vitreous
(H) posterior to lens; gel-like
Chloroid
(T) blood rich, dark pigment, keeps light from scattering; anterior to Iris
Fovea Centralis
(T) lateral to optic disc; has only cones; gives you sharpest vision
Retina
(T) sensory, delicate, white, abalone-esque, contains millions of receptors
Rods
(part of retina) give you "night-vision;" beta-carotene is very good; densest at periphery
Cones
(part of retina) give you color vision, details; densest at center
Colorblindness
When one or more of the cones which filters only green, blue and red light, does not work
Optic Disc
(part of Fovea Centralis) no photoreceptors where optic nerve leaves retina
Lens
focus light on retina (flexible biconvex structure); attatched to ciliary body by ligaments; lets you focus
Cataracts
when the lens becomes hard, opaque; symptoms are: hazy vision, blindness
