Brainscape's Knowledge GenomeTM

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


See full index

BV and Optometric Neurophysiology > Depth perception and Stereopsis > Flashcards

Depth perception and Stereopsis Flashcards

1
Q

What are the monocular cues for depth perception?

A

Lighting/shading
Texture gradient
Hue attenuation
Overlapping
Motion parallax
Linear gradient
Aerial perspective
Retinal image size
Accommodation

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

What is the monocular cue lighting/shading?

A

Light or shade gives clues as to whether an object is pointing/moving towards or away from you

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

What is the monocular cue texture gradient?

A

Textures become less detailed as they become further away from you

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

What is the monocular cue hue attenuation?

A

The moisture particles in the air make objects appear a lighter hue when far away

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

What is the monocular cue overlapping?

A

If one object is in front of another, it appears to overlap the object behind it

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

What is the monocular cue motion parallax?

A

Closer objects appear to move faster than objects that are further away

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

What is the monocular cue linear gradient?

A

Lines get closer together as they get further away from you

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

What is the monocular cue aerial perspective?

A

seeing something from above indicates that it is far away

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

What is the monocular cue retinal image size?

A

Known object sizes are used to judge how far away something is

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

What is the monocular cue accommodation?

A

If accommodation is being used, you know that the object is closer (subconsciously)

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

What are the binocular cues to depth perception?

A

Objective Fronto-parallel plane
Vieth-Muller circle
Horopter

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

What is the Objective Fronto-parallel plane?

A

A straight plane in front of you, parallel to the plane which passes through the pupils.
Anything in front or behind the plane gives clues to depth

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

What is the Vieth-Muller circle?

A

A circle encompassing the objects in front of you and their corresponding retinal points
Depth able to be perceived from awareness of which corresponding points are being stimulated

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

What is the horopter?

A

Curved plane, all points stimulating corresponding retinal points
Able to tell depth from what is on the plane, just in front and behind in Panum’s area, and outside of Panum’s area

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

What is binocular rivalry?

A

During physiological diplopia, the brain chooses the ‘better’ image to avoid double vision in the periphery. Often more dominant eye’s image chosen, but if image better in other eye, this will be chosen.

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

For smaller stimuli, what type of dominance is used in binocular rivalry?

A

Exclusive - only one image used

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

For larger stimuli, what type of dominance is used in binocular rivalry?

A

Mosaic - elements from each image used which are constantly shifting/alternating

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

What details are prioritised during binocular rivalry?

A

Detail
Lines/contours
Movement
High contrast
Brighter
Flash

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

Why does physiological diplopia occur?

A

Anything outside of Panum’s area is seen on non-corresponding points, so the cyclopean eye sees two of the object.

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

What level of stereopsis are you able to measure up to in a normal clinic?

A

60” arc

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

What is the timeline for stereopsis development?

A

Starts to develop at 3 months, rapid until 18 months, continues until at least 3 years old

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

What factors affect/limit stereopsis?

A

Blur
Motion-in-depth
Temporal characteristics
Contrast sensitivity
Retinal eccentricity
Distance

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

Why does blur affect/limit stereopsis?

A

Detail not as clear - unilateral is worse than bilateral bc harder to detect corresponding points

24
Q

Why does motion-in-depth affect/limit stereopsis?

A

Harder to locate corresponding points - more retinal disparity

25
Q

Why do temporal characteristics affect/limit stereopsis?

A

If something is seen for less time, then it’s harder to gather information about it and coordinate corresponding points/retinal disparity

26
Q

Why does contrast sensitivity affect/limit stereopsis?

A

Higher contrast is easier to tell difference between things - unilateral is worse than bilateral

27
Q

Why does retinal eccentricity affect/limit stereopsis?

A

Further into periphery is worse due to lack of detail available to find retinal disparity

28
Q

Why does distance affect/limit stereopsis?

A

If something is further away, you can see less detail, so it’s harder to distinguish corresponding points and therefore create retinal disparity

29
Q

What are the methods of assessing stereopsis?

A

Free fusion
Auto-stereogram
Anaglyphs
Vectographs
Transparent plates
Synoptophore

30
Q

What kind of disparity is created when objects are behind the horopter?

A

Uncrossed disparity (image is on nasal retina)

31
Q

What kind of disparity is created when objects are in front of the horopter?

A

Crossed disparity (image is on temporal retina)

32
Q

What level can the Lang test up to?

A

100/200” arc

33
Q

What level can the TNO test up to?

A

60” arc
(15” arc on older versions)

34
Q

What level can the Titmus test up to?

A

Fly: 800-3000” arc
Circles: 800-40” arc
Animals: 400-100” arc

35
Q

What level can the Frisby test up to?

A

600-5” arc

36
Q

What is point zero?

A

The point on the retina where the target’s image falls in a strabismic eye

37
Q

What is confusion?

A

Different images are seen on each retina due to strabismus, with diplopia also present
Brain cannot tell which image is ‘correct’

38
Q

In an esot, where does the image fall and which field is it seen in?

A

Falls nasal to fovea
Seen temporally

39
Q

In an exot, where does the image fall and which field is it seen in?

A

Falls temporal to fovea
Seen nasally

40
Q

What is a suppression scotomata?

A

Area between the fovea and point zero where suppression occurs

41
Q

What are binocular adaptations to a strabismus/diplopia caused?

A

Suppression
Abnormal retinal correspondence

42
Q

What are monocular adaptations to a strabismus/diplopia caused?

A

Amblyopia
Eccentric fixation

43
Q

What does binocular adaptation mean?

A

It can only be present when both eyes are open/not covered

44
Q

During foveal suppression, does diplopia still occur?

A

Yes, in peripheral locations (anywhere that isn’t within suppression scotomata)

45
Q

What is ARC?

A

The corresponding points in the retina of the strabismic eye are ‘readjusted’ so double vision doesn’t occur
Foveal suppression/scotomata are still present

46
Q

What is harmonious ARC?

A

Adjustment made = objective deviation size (Prism CT result)
PZ becomes fixation point, lines up with fovea in fixating eye

47
Q

What is unharmonious ARC?

A

Adjustment made = subjective deviation size
Fixation point is between fovea and PZ

48
Q

Why does unharmonious ARC occur?

A

Due to a change in the angle of the strabismus, normally from surgery or trauma

49
Q

What is amblyopia?

A

Reduced VA by at least 2 lines in one eye despite being fully corrected and no pathology present

50
Q

When can amblyopia be bilateral?

A

When there is high uncorrected astigmatism (meridional amblyopia)

51
Q

What are the causes of amblyopia?

A

Anisometropia
Stimulus deprivation (congenital cataracts)
Refractive error
Strabismus
Early eye disease
Nutritional/toxic
Idiopathic or congenital

52
Q

What is eccentric fixation?

A

Fovea doesn’t take up fixation when fixating eye is covered bc the brain has ‘moved’ fovea to a different retinal point - so image is still on fixation point when covered

53
Q

What is EC with Identity?

A

The fixation point is on PZ, no movement on CT

54
Q

What is EC without Identity?

A

The fixation point is in between the fovea and PZ, some movement on CT

55
Q

What is intractable diplopia?

A

Constant, unchangeable diplopia

BV and Optometric Neurophysiology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions