eye, vision

Question 1

what are the 3 parts of the eye (main)

Answer 1

pupil, iris, scalera

Question 2

what is a scalara coil

Answer 2

measures eye movement by sitting on the eye

Question 3

where does light hit after passing the cornea

Answer 3

to the retina

Question 4

high center of what in the middle of the retina

Answer 4

photoceptors

Question 5

what are the muslces attaching the lense and change shape of lense

Answer 5

ciliary muscles

Question 6

what can the cillry muscles do

Answer 6

change shape of the lens

Question 7

how does the brain reverse image

Answer 7

left to right

Question 8

post retinal processing is what

Question 9

what is a diopter

Answer 9

is a measure of lens focussing power - reciprocal of focal length in meters - 1D=1m

Question 10

what 2 things effect lens strength

Answer 10

curvature and refractive index

Question 11

how does the lens change shape

Answer 11

either curved and oval or flat - aka accomodation

Question 12

ciliary muscles can contract and relax - which is loosening of fibres

Answer 12

contract

Question 13

what state will your eye be if relaxed

Answer 13

focusing on something’

Question 14

round shape is for what

Answer 14

close object

Question 15

flat lens is for what

Answer 15

something far away

Answer 16

parasympathetic nervous system

Question 17

concave lens of glasses is

Answer 17

short sighted

Question 18

short sighted is aka

Answer 18

myopia

Question 19

how does a concave lens help

Answer 19

reduces the refraction and focus

Question 20

what is hypermetropia

Answer 20

far sighted

Question 21

how does the pupil adapt to light

Answer 21

changes diameter- smaller = too much light VV

Question 22

whats the range for pupil size when changing

Answer 22

2-8mm

Question 23

whats the proper name for pupil

Answer 23

sphincter pupillae

Question 24

why is a smaller pupil better

Answer 24

links to more light be accessible but also creates a high quality image - like a pinhole camera which has more depth

Question 25

depth of field is what when small pupil

Answer 25

longer / deeper

Question 26

pupil size can help with which condition

Answer 26

myopia

Question 27

what is a ophthalmoscope

Answer 27

an object that shines light into a retina

Question 28

photoreceptors in high amount are where

Answer 28

retina middle

Question 29

rods and cones make up what

Answer 29

photoreceptors

Question 30

what are the 5 cells in photorecptors

Answer 30

cones/rods, horizontal cells, biopolars, ganglai cells and amacrines

Question 31

what do ganglia cells do

Answer 31

fire like neurons

Question 32

do photorecptors have ap

Answer 32

no

Question 33

do ganglia in photorecptors have ap

Answer 33

yes

Question 34

what forms the optic nerve

Answer 34

ganglai cells

Question 35

why are structures in the front foveal receptors pushed to one side

Answer 35

reduces light / scatter absorption

Question 36

what is acuity

Answer 36

sharpness

Question 37

what happens to receptors when they are saturated and cannot detect light

Answer 37

they become bleached

Question 38

what is photopigment

Answer 38

a pigment that the chemical state depends on its degree of illumination

Question 39

what 2 molecules used to form photopigment

Answer 39

retinal and opsin

Question 40

retinal and opsin are the what state

Answer 40

bleached

Question 41

the light photon interacts with rhodopsin causes what

Answer 41

configurational change

Question 42

released opsin activates PDE - phosphodiesterase via ...

Answer 42

transducin G protien

Question 43

closure of NA channels cuases hypeerpolerisation of cell due to what leak

Answer 43

K

Question 44

ganglion cell modifies the membrane potential of a what cell

Answer 44

bipolar

Question 45

changes in firing of ganglion cell bipolar can be

Answer 45

excitatory or inhibitory

Question 46

rod and cone hyperpolarization results in less

Answer 46

neurotransmitter release - glutamate

Question 47

what is the unit that the eye can function across of luminance

Answer 47

10^15

Question 48

what is scotopic vision

Answer 48

low light vision

Question 49

are rods or cons for low light

Answer 49

rods - because low acuity and high sensitivity

Question 50

is high light / photopic rods or cones

Answer 50

cones only - too much light will bleach the rods

Question 51

mesopic is what

Answer 51

medium light level

Question 52

mesopic what levels is everything

Answer 52

medium

Question 53

does mesopic have rods or cones

Answer 53

both

Question 54

what are the 4 mechanisms adapting to lumminance

Answer 54

pupil size, cones and rods switch dark adaptation ( bleaching and regeneration) and field adaptation

Question 55

what is field adaption

Answer 55

light adaptation, automatic gain control within photoreceptor - calcium release mechanism

Question 56

sensitivity verus acuity is what

Answer 56

an adaptation which is a constant trade-off of the 2

Question 57

Rods are more sensitive than cones t or f

Answer 57

T

Question 58

how long does it take to regenerate rods cells

Answer 58

20min

Question 59

under mescopic conditions rods and cones may..

Answer 59

converge together

Question 60

visual sesnitivity gradually increases over 20min in

Answer 60

dark

Question 61

cones adapt faster but rods

Answer 61

take over as their threshold is lower

Question 62

field adaptation copes with fast ..

Answer 62

changes in light

Question 63

biopolars, horizontals and amacrines do what

Answer 63

retinal processing partically, reducing things of interest, changes - spacial and temporal

Question 64

the ganglion cell is the final output of what

Answer 64

the retina

Question 65

each ganglion cell may repsond to

Answer 65

many photoreceptors

Question 66

use light shone on a retina to find what

Answer 66

the ganglion receptive field

Question 67

Some photoreceptors excite the ganglion cell, some inhibit. Forms a centre-surround shape, causing

Answer 67

lateral inhibition

Question 68

lateral inhibition is

Answer 68

mediated by horizontal cells

Question 69

lateral inhibition explained-

Answer 69

the surrounding context impacts what your retina sees

Question 70

1 rod cell and 3

Answer 70

cone cell

Question 71

what can colour be defined by 2

Answer 71

saturation and hue

Question 72

where does colour processing take place

Answer 72

the retina

Question 73

ganglion cells dont respond to which colours

Answer 73

green blue or red - alone but do combinations

Question 74

colour constancy is ..

Answer 74

when colours tend to look the same despite large changes in wavelength of illuminating light

Question 75

colour blind or deuteranope is

Answer 75

lack of green receptor

Question 76

which part of brain does a left visual enter

Answer 76

right

Question 77

where does the optic nerve split

Answer 77

optic chiasm

Question 78

informtaion if relayed to where via the lateral geniculate nucleus - in thalamus

Answer 78

visual cortex