6 - Visual System

Question 1

what percent of our perception, learning, cognition, and activities are mediated through vision?

Answer 1

80%

Question 2

cornea

Answer 2

transparent layer at the front of the eye, allowing light in
- can bend and refract light

Question 3

lens

Answer 3

can also direct light by changing shape of the lens from ciliary eye muscles which help maintain focus for eyes at varying distance

Question 4

what surgery replaces a cloudy lens?

Answer 4

cataract

Question 5

pupil

Answer 5

opening at the center of the iris

Question 6

iris

Answer 6

colored part of the eye regulating the light through changes in diameter

Question 7

retina

Answer 7

• neural structure of the eye
• detects light and translates this into neurological impluses for brain to interpret

Question 8

which eye structure is considered part of the CNS?

Answer 8

retina

Question 9

blood supply for the eye

Answer 9

opthalmic artery and the central retinal artery which branch from the internal carotid artery

Question 10

what is the binocular zone?

Answer 10

portion of visual field where light falls upon both retinas
(what can see with both eyes)

Question 11

what is the monocular zone?

Answer 11

part of visual field where light falls only on one retina

Question 12

the primary visual cortex is also known as…

Answer 12

Brodmann’s area

Question 13

what percent of each optic nerves crosses at the optic chiasm?

Answer 13

60% cross

Question 14

where does the lateral geniculate body receive information from?

Answer 14

the opposite visual field

Question 15

the L lateral geniculate body receives information from ______ half of L retina and _______ half of R retina

Answer 15

temporal half of L retina
nasal half of R retina

Question 16

the central visual field is at the _______ pole

Answer 16

occipital pole
(most posterior part of the brain)

Question 17

the peripheral visual field is ______ from the occipital pole

Answer 17

anterior

Question 18

the lingual gyrus contains the ______ visual field, _______ the calcarine fissure

Answer 18

upper visual field
below the calcarine fissure

Question 19

the cuneus contains the _______ visual field, ______ the calcarine sulcus

Answer 19

lower visual field
above the calcarine fissure

Question 20

the R visual field is in the ____ occipital lobe

Answer 20

left occipital lobe

Question 21

how does visual information come to the visual cortex?

Answer 21

as temporally and spatially organized trains of action potentials, not as images?

Question 22

how do these APs get transformed into images?

Answer 22

• one portion of info is processed and then passes to temporal lobe for object identification
• another part is passed to parietal lobe for spatial features and movement of object

Question 23

what is brought together for visual information to be useful for us

Answer 23

visual info, prior experience, emotions

Question 24

facial agnosia

Answer 24

restricted coritcal lesions may produce inability to recognize faces or objects
(can’t integrate infor)

Question 25

visual field defect occurs with lesions in the _____ __________

Answer 25

optic radiation

Question 26

visual changes contribute to visual ______ and lack of ________

Answer 26

neglect awareness

Question 27

astigmatism

Answer 27

causes blurred or distorted vision at any distance due to abnormal shape of the cornea or lens

Question 28

what is the treatment for astigmatism?

Answer 28

corrective lenses or surgery

Question 29

strabismus

Answer 29

eye disorder that causes the eyes to be misaligned and not look at the same object at the same time (impairments with the muscles)

Question 30

what is the treatment for strabismus?

Answer 30

surgery, prism lenses

Question 31

presbyopia

Answer 31

refractive error that occurs as people age, causing difficulty seeing objects up close (normal process of aging, ~40-50 yrs)

Question 32

what is the treatment for prebyopia?

Answer 32

readers, lens replacement

Question 33

myopia

Answer 33

near sightedness, difficulty seeing objects that are far away, shape of the eye causing light rays to bend incorrectly

Question 34

what is the treatment for myopia?

Answer 34

glasses, contact lenses, or laser surgery

Question 35

cataracts

Answer 35

clouding of the eye's lens, increases with age, which prevents light from focusing on the retina

Question 36

what is the treatment for cataracts?

Answer 36

lens replacement

Question 37

glacuoma

Answer 37

build up of fluid resulting in increased pressure behind the eye, damages peripheral vision first, increases with age

Question 38

what is the treatment for glaucoma?

Answer 38

eye drops, laser/surgery, neg pressure goggles

Question 39

macular degeneration

Answer 39

disease that damages the macula, the part of the retina that controls central vision, wet and dry types, increases with age (struggle to see central vision)

Question 40

what is the treatment for macular degeneration?

Answer 40

no cure but can clow with specialized meds, vitamens, and possible surgery