Vision

Front 1

Eyebrows

Back 1

Located superior to the eye, partially shade the eyes and protect from sweat

Front 2

Eyelids

Back 2

Located over the eye. Blink to moisten eye and sweep foreign substances from eye's surface

Front 3

Eyelashes

Back 3

Located on the margin of eyelids. Prevent foreign substances from entering

Front 4

Lacrimal Apparatus

Back 4

Composed of the lacrimal (tear) gland and lacrimal ducts. Secretions or tears from the gland moisten the eye and washes away foreign substances.

Front 5

Conjuctivia

Back 5

Epithelial covering on the inside of the eyelid and the anterior surface of the eye.

Front 6

Oblique eye muscles

Back 6

Superior oblique rotates the eye downward and medially. Inferior oblique rotates the eye upward and medially.

Front 7

Rectus Eye Muscles

Back 7

Four muscles are superior, inferior, medial, and lateral. Move eye up, down, medially, and laterally.

Front 8

Aqueous and Vitreous Humours

Back 8

Jelly-like fluids that fill the interior of the eye.

Front 9

Sclera

Back 9

Commonly called the white of the eye. Tough, tendon-like layer continuous with the dura mater of the brain around the optic nerve. Shapes the eye.

Front 10

Cornea

Back 10

Most anterior layer of eye that is continuous with sclera. Transparent to allow light into the eye. Well supplied with nerve endings for pain, reflex blinking, and to stimulate lacrimal secretions. Lacks blood vessels.

Front 11

Choroid

Back 11

Separates the fibrous and sensory tunics. Contains a dense capillary bed that provides oxygen and nourishment to the eye. Also contains melanocytes for dark appearance

Front 12

Iris

Back 12

Lies just beneath the cornea. Layer to which we attribute eye color. Composed of two layers of pupillary muscles that control the diameter of the pupil. and thus the amount of light entering the eye.

Front 13

Pupil

Back 13

The round central opening in the center of the eye

Front 14

Ciliary body

Back 14

A thick ring of tissue attached to, and lies just beneath, the iris. Anchored at its margins by the choroid.

Front 15

Lens

Back 15

Located beneath the iris and held in the center of the pupil by suspending ligaments extending from the ciliary body. Transparent and convex on its outer and inner surfaces. Focuses an image on the retina by changing shape under the influence of the ciliary muscles.

Front 16

Retina

Back 16

The delicate, two innermost layers of the eye. Neural layer contains photoreceptors and neurons that react to light and transmit and integrate visual signals. Beneath the neural layer lies the pigmented layer. It absorbs light that has passed through the neural layer to prevent the light from bouncing back and causing visual echo.

Front 17

Rods

Back 17

Photoreceptor cells very sensitive to light. They enable us to see shades of gray in dim light.

Front 18

Cones

Back 18

Photoreceptor cells responsible for high acuity color vision. They only operate in bright light. There are three types of cones: sensitive to red, green, or blue light.

Front 19

Bipolar Neurons

Back 19

Synapse with the dendrites of the rods and cones. Transmit nerve impulses to the ganglion cells.

Front 20

Ganglion Cells

Back 20

Synapse with the axons of the bipolar neurons. The icons combine to form the optic nerve, which sends nerve impulses to the brain.

Front 21

Optic Disc

Back 21

Where the optic nerve leaves the eye. Not covered by the retina. A blind spot in the eye.

Front 22

Optic Nerve

Back 22

Cranial Nerve II: It transmits visual information from the eye to the brain

Front 23

Fovea Centralis

Back 23

The portion of the retina that is responsible for sharp central vision. Humans use this region for any activity that requires detailed vision, such as driving.