1. The Eye

2. Parts of the Eye
Sclera: connective tissue that makes up the outer surface of the eye
Choroid: pigmented layer surrounded by the sclera; this forms the iris
Iris: gives the eye it’s color; muscles in the iris regulate the size of the pupil so it regulates the amount of light coming in to the eye
Cornea: clear tissue covering the front of the eye; purpose is for protection and initial focusing of light coming in to the eye

4. Parts of the Eye
Pupil: opening in the center of the iris that lets light into the interior of the eye
Lens: located behind the pupil and is responsible for flipping the image (so it is upside-down) before it reaches the retina
Retina: layer of receptor cells that line the back of the eye; these receptor cells respond to light and there are two kinds
Rods: responsible for seeing black and white at night
Cones: responsible for color vision
Rods = peripheral vision/ are less sensitive to color/ many more of these than cones
Retina = transparent and flexible; helps focus light also

5. Light hits the rods and cones and nerve impulse begins
Light hits the rods and cones and nerve impulse begins. The impulse is carried, via the optic nerve (the sensory neuron in the eye), to the visual centers in the brain (occipital lobe). The brain then flips the image again so it’s right-side-up.

6. Pupil {

7. There are two fluids in the eye:
Aqueous humor: located in the chamber in front of the pupil/iris
This liquid is secreted by capillaries and is responsible for supplying the lens, iris, and cornea with nutrients and oxygen, and carries off waste.
Glaucoma results when the fluid can’t drain properly through tiny ducts near the iris and a blockage occurs.
Vitreous humor: located in the chamber behind the lens
Contains a transparent, jelly-like substance that gives the eye its shape.

8. Pupil {

9. Pupil {