Visual System - Lecture 8 Flashcards
eyes are the window to the soul
brain and eye development are closely linked in utero
does the visual system create an exact copy of the external world
yes
what does the visual system create
perception of reality
how do we rely on vision
heavily for balance
–>visual, vestibular, somatosensory
what does vision do overtime
decays over time
gets worse as we get older
what is the primary CN for vision
CN2
CNs for extraocular muscles
3,4,6
binocular disparity
most mammals have 2 eyes on the front of their heads
what does binocular disparity do
cuts down the field of view
insures most of what is seen through both eyes
we can see past midline
what is slightly different b/w both eyes
perspective
difference b/w 2 retinal images
what is binocular disparity greater for
closer things
what is the degree of binocular disparity associated with
particular visual stimulus
helps the brain create 3-D perception from 2-D retinal images
can we still perceive depth with one eye close
yes
depth perception CN
2
what percentage of all sensory receptors are in the eyes
70%
what percentage of the cerebral cortex is involved in processing visual info
40%
external structures of the peripheral NS
orbit
palpebrae
orbit
bony socket
what does the orbit contain
eye
orbital fat
fascia
levator muscle of the upper lid
lacrimal gland
extraocular muscles
nerves and blood vessels
how many bones form the orbit
7
what is the palpbrae
eyelids
what do the palpbrae do
protect the eye and help replenish the tear film
what is in the palpbrae
orbicularis oculi muscle
levator palpebraer superioris muscle
orbicularis oculi muscle
occupies the entire length of the eyelid
responsible for closure
CN7
