Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

2nd Sem > P2 - Orthoptics > Flashcards

P2 - Orthoptics Flashcards

1
Q

are fast, ballistic eye movements that abruptly change the point of fixation

A

Saccadic system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the eye movement systems

A

Saccadic system
Smooth pursuit system
Vergence system
Vestibulo-ocular movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Saccadic System

include willed refixations, those in response to command and memory-guided saccades

A

Voluntary movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Saccadic system

include saccades in the direction of a new stimulus that may be visually guided (prosaccade) or in response to an auditory stimulus, accompanied by head movement in the same direction

A

Reflex movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Saccadic system

After onset of a target saccade it takes (latency) about how many millisecond for eye movement to begin

A

200ms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Saccadic system

Maximum velocity is up to

A

500°/s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

are much slower tracking movements of the eyes designed to keep moving stimulus on the fovea

A

Smooth Pursuit System

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

under voluntary control in the sense that the observer can choose whether or not to track a moving stimulus

A

Smooth pursuit system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

It is one of the two ways that visual animals can voluntarily shift ggaze, the other being Saccadic eye movements

A

Smooth pursuit system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the stimuli in smooth pursuit system

A

fixated targets that moves across the foveal and perifooveal retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

tested by placing a subject inside a rotating cyl with vertical stripes (subject is seated in front of a screen on whoch a series of horizontally moving vertical bars is presented to conduct this optokinetic test)

A

Smooth pursuit system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

is a normal reflexive response of the eyes in response to large-scale movements of the visual scene & should not be confused w pathological nystagmus that can result from kinds of brain injury

A

Optokinetic Nystagmus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Maximum speed of OKN

A

90°/sec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Latency of OKN

A

125 ms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

can be elicited voluntarily, but occur reflexively whether the eyes are open, even when fixated on a target

A

Saccadic system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

small movements made while reading

A

Saccadic system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

rapid eye movements that occur during an important phase of sleep

A

Saccadic sytem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

much larger movements made while gazing around a room

A

Saccadic system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

under both volitional and reflex control

A

Saccadic system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

are disjugate and smooth where one eye can move independently of the other

A

Vergence system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

occur as synkinesis with accommodation of the lens & pupillary constriction

A

Vergence system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What rectus muscles are innervated during vergence movements

A

Medial & Lateral Recti motorneurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

may occur as Saccadic or Smooth pursuit movements, and therefore cortical areas relating to generation of these eye movements will be involved in the cortical proceesing of visual information

A

Vergence eye movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Vergence system maximum velocity

A

20°/sec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Vergence system latency

A

160ms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is the stimuli of vergence system

A

disparity between location of images on the retina of each eye, resulting in fusional vergence & retinal blur caused by loss of focus of images, which results in accommodative vergence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

stabilize the eyes relative to the external world, thus compensating for head movements

A

Vestibulo-ocular movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

reflex response prevent visual images from “slipping” on the surface of the retina as head position varies

A

Vestibulo-ocular movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

can be appreciated by fixatiing an object and moving the head from side to side

A

Vestibulo-ocular movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

intergrates eye and body movements and is not dependent on ocular stimulation but is concerned with head position & balance

A

Vestibulo-ocular movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Vestibulo-ocular movements maximum speed

32
Q

Vestibulo-ocular movements latency

33
Q

the false localisation of objects in space in px with recent paresis due to sensory changes resultimg from alterned alignment of the eye

A

Past-pointing

34
Q

Left LR paralyzed and OS attempts (OD is occluded) to look at an object to the left, that object will be thought to be located further to the side than it actually is)

A

Past-Pointing

35
Q

VA: Visual perception of an object is resolved according to:

A
  1. light sense
  2. form sense
  3. form sense
36
Q

is the absolute threshold of light

A

Light sense

37
Q

what are the two Form Sense

A

Central vision
Peripheral vision

38
Q

is inclusive of VA and Contrast sensitivity

A

Form sense

39
Q

the ability to discriminate fine high contrast detail

A

Central vision

40
Q

the field of vision

A

Peripheral vision

41
Q

Variables that affect VA

(RECCO)

A
  1. Retinal stimulation
  2. Contrast
  3. Eye movements
  4. Contour interaction
  5. Occlusion
42
Q

central stimulation involves the fovea with higher acuity function, luminance (brightness of target)

A

Retinal stimulation

43
Q

sensitivity to background lighting

44
Q

even when looking steadily at tragets there are constant refixation movements to maintain central fixation

A

Eye movements

45
Q

it is easier to identify a target presented singly than one with other surrounding stimuli

A

Contour interaction

46
Q

this may be by hand, atropine, high plus lens, blenderm, opaque (glasses, opaque patch, opaque occluder or Spielmann occluder)

47
Q

what are the Qualitative Clinical Vision Tests

A
  • Fixation
  • Cover test
  • Visually directed-reaching
  • 100s & 1000s
  • Catford drum
  • Stycar Rolling/Mounted balls
  • Ten Dioptre Prism
  • Mirror test
48
Q

Qualitative test

observe pursuit movement and fixation preference

49
Q

Fixation

Fixation preference detects what if the deviation exceeds 10 prism dioptres

50
Q

What is the fixation preference in the presence of strabismus

A

it may show equal alteration, fixation held through a blink, fixation held briefly, fixation held with difficulty or no fixation held with stabismic eye

51
Q

uniocular fixation & objection to occlusion

A

Cover test

52
Q

reaction to visual stimulus by reaching towards the object of interest

A

Visually-directed reaching

53
Q

response to small sweets & indicates acuity of approximately 6/24

A

100s & 1000s

54
Q
  • moving dots or gratings
  • fast saccades
  • for infants and preschool
A

Catford drum

55
Q
  • graded balls in various sizes mounted/rolled along floor
  • pursuit eye movements
A

Stycar rolling/Mounted ballss

56
Q

assess fixation preference in preverbal children who are not strabismic or who have small deviations

A

Ten Dioptre Prism

57
Q

In 10D prism, it is recommended that the prism be held ____ in cases of ptosis to aid accuracy in detecting eye movement response

58
Q
  • performed base down or base up
  • a 25-dioptre base-in prism may also be used
A

Ten Dioptre Prism

59
Q

the infant is held close to a mirror so that they can look at their own reflection

A

Mirror test

60
Q
  • the distance of the infant from the mirror is increased until they no longer look at themselves
  • this test is useful as it is portable and easy to administer
A

Mirror test

61
Q

what are the Quanttitative clinical vision tests
(FTNPCC)

A
  • Forced Choice Preferential Looking Cards (FCPL)
  • Teller Acuity Cards
  • Near test
  • Pinhole
  • Crowding phenomenon
  • Contrast sensitivity
62
Q

the test cards consists of a black & white grating placed on the left or riight of the card

63
Q

the observer records the direction of head movements in response to the appearance of striped stimulus

64
Q

VA determined with FCPL range

A

Newborns: 6/240
3 months: 6/60
36 months: 6/6

65
Q

introduce a set of 16 cards that consisted of a grey background with a square wave grating on on side

A

Teller Acuity Cards

66
Q

process is undertaken at a testing distance of 38 or 55cm. Eye movements are observed towards the position of the stripes

A

Teller Acuity Cards

67
Q

What are the Near Tests

A
  • Reduced Snellen test
  • Reduced Sheridan Gardiner
  • Reduced E test
  • Maclure book
  • Moorfields bar reading book
  • N series test
68
Q

used to assess whether or not reduced vision is caused by uncorrected refractive error

69
Q

when vision improves this is indicative of refractive error, if no improvement occurs, there is amblyopia, or some organic cause for reduced vision

70
Q

easier to see a single optotype than a letter on a linear chart

A

Crowding phenomenon

71
Q

the reduced VA is due to the additional stimuli from surrounding letters & results in confusion

A

Crowding phenomenon

72
Q

specifically caused by contour interaction and attentional factors, this is noted in particular with reduced VA in amblyopes

73
Q

the ability to distinguish between different levels of contrast

A

Contrast sensitivity

74
Q

uses sine waves, continuous waveforms that oscillate in smooth & regular manner and can be of diff freqiencies and amplitudes

A

Contrast sensitivity

75
Q

Contrast sensitivity

it is the number of cycles per degree: one cycle includes one dark and one light area

A

Spatial frequency

76
Q

condition when tthe eye deviates from parallelism when fusion has been broken

A

Heterophoria

2nd Sem (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions