1. SENSORY SYSTEM
FUNCTION OF THE EYE

2. EYE Protected by orbit, eyebrows, eyelashes, eyelids
Lacrimal glands – tears empty into nasal cavity and clean the eyes
Conjunctiva – secretes mucous to lubricate eyes

3. SCLERA and CORNEA Sclera: Tough coating, helps maintain shape of eye
Extrinsic muscles - responsible for moving eye attached to sclera
Cornea:
Transparent so light rays can pass through

4. CHOROID COAT Middle layer, contains blood vessels
Intrinsic muscles – change size of iris to control amount of light entering through pupil
Pupil constricts:
Gets smaller (in bright light)
Pupil dilates
Gets larger (in dark light)

5. LENS Where light rays are refracted Accommodation:
Change in the shape of the lens to allow for near and distant vision

6. RETINA Light rays focus image on retina
Image travels to the cerebral cortex via optic nerve
Rods – sensitive to dim light
Cones – sensitive to bright light and color
Optic disc – on retina, known as blind spot, nerve fibers that form optic nerve

7. PATHWAY OF VISION
Image travels through cornea, then pupil, through lens, light rays are bent or refracted, hits retina, picked up by rods and cones and carried to optic nerve, then to occipital lobe where the brain interprets image
Figure 10-7 pg. 193