Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Block 5 > Optics: Axes And Angles > Flashcards

Optics: Axes And Angles Flashcards

1
Q

Any two optical systems is required to be aligned ___________ to do efficient transmission

A

Coaxially

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

The human eye have ___ major optical surfaces, ___ aperture, and the retina

A

4, 1

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

The optical and neural components of the eye are ___________ attached and objects are placed on-axis by _________________

A

Rigidly, rotating the eye

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

There is a superior signal transmission when…

A

Optical and neural axes are aligned with each other

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

Optical and neural axes of the eye:

A
  1. Optical axis
  2. Visual axis
  3. Pupillary axis
  4. Line of sight
  5. Achromatic axis
  6. Fixation axis
  7. Keratometric axis
  8. Receptor axis
  9. Neural axis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Optical axis of the eye

A

Axis containing the centers of curvature of the eyes optical surfaces

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

Optical axis is a _______ line along which…

A

Straight, a ray both enters and exits the system

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

Rotationally symmetric optical systems need one axis. Which axis?

A

Optical axis

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

Non-rotationally symmetric systems need more _____

A

Axes

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

Visual axis:

A

The line connecting the fovea and the fixation point passing through the nodal points

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

Place of intersection of visual axis with the cornea is called ___________________

A

Ophthalmometric pole

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

Ophthalmometric pole is used to…

A

Characterize the cornea exactly

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

The curvature of the cornea __________ as it moves away from apex.

A

Flattens

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

The ophthallmometric pole is NOT influenced by:

A

-pupil fluctuations or accommodation

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

The visual axis is convenient reference point for ________________

A

Visual functions

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

Visual axis does NOT depend on:

A

Pupil position

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

Visual axis acts are the reference point for:

A

-alignment of corrective lenses
-determinations of treatment location for laser procedures
-positioning of IOL during cataract surgery
-alignment of visual axes between both eyes

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

Pupillary axis:

A

Line normal to the cornea passing through the center of the pupil

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

Pupillary axis is used for….

A

Aligning optical instruments to the eye

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

The pupillary axis is used as an objective measure to judge the amount of _____________ fixation

A

Eccentric fixation

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

Eccentric fixation

A

Retinal point other than the center of the fovea is used for fixation (adaptation to heterotropia)

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

Hadingers brush apparatus is used to:

A

Detect, diagnose, and train amblyopia due to eccentric fixation

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

Acuity is reduced in eccentric fixation because…

A

The person fixates with a part of the peripheral retina instead of macula

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

Line of sight:

A

Ray from fixation point that reaches the foveolar via center of the pupil

25
Position where line of sight intercepts the cornea is called:
Corneal sighting center
26
Line if sight is critical during:
-VF testing -refractive surgery planning -macular disease evals
27
Achromatic axis:
Line connecting the nodal point and the center of the pupil
28
Achromatic axis is also called the…
Fovea achromatic axis
29
The ray passing through the achromatic axies does NOT..
Suffer from any transverse chromatic aberration
30
Achromatic axis is similar to optical axis, but dependent on ______________
Pupil position
31
Fixation axis:
Line passing through the fixation point and the center-of-rotation of the eye
32
The fixation axis is the reference for measuring __________________
Eye movements
33
Fixation axis is an ________________ and depends on the direction of ____________
Approximation, rotation
34
Fixation axis is important for:
-eye elignment -strabismus -refractive surgery
35
Keratometric axis:
Line passing through the fixation point and the center of curvature of anterior cornea
36
Keratometric axis is used for…
Alignment in topography measurements
37
Point at which the Keratometric axis intercepts the cornea is called:
Vertex normal
38
Photoreceptor axis :
????
39
Neural axis:
????
40
Angles between axes:
-angle alpha -angle lambda -angle kappa -angle psi -angle gamma
41
Angle alpha:
-Angle between the optical and visual axis -formed art first nodal point
42
Angle alpha is positive when:
The visual axis is on the nasal side of the optical axis in object space
43
Angle alpha primary application:
-Guiding the placement of the IOL during cataract surgery **large angle alpha causes issues with lens contraction and visual quality
44
Angle lambda:
Angle between the pupillary axis and the line of sight
45
Angle lambda is the angle formed at the…
First nodal point by the optical and visual axis of the eye
46
For most patients, the pupillary axis is ____________ to the line of sight in _____________ space . Making a ________ angle
Temporal, object, positive
47
Angle lambda application:
Ensure accurate contraction during ant seg surgeries like corneal transplants or laser refractive procedures
48
Large angle lambda can lead to…
Misalignment of the surgical site or implanted device
49
A normal angle lambda indicates the corneal light reflex is ______________ to the pupillary center reflecting _______________ if the visual axis
Slightly nasal, proper alignment
50
Angle kappa:
Angle between the pupillary axis and visual axis (angle kappa is same as angle lambda)
51
Large Angle kappa clinical implications:
-hyperopic pts have large K values -increased risk of patients complaints of post-operative glare and halo
52
Angle psi:
Angle between the visual axis and achromatic axis (both planes pass through nodal points)
53
Positive sign angle psi indicates:
Visual axis is inclined along the nasal side
54
Mean value for angle psi:
+2.1 degrees
55
Angle gamma:
Angle between the optical axis and fixation axis
56
Angle gamma is within _____ of angle alpha for object distances greater than 50cm
1%
57
Application of angle gamma:
-Identify situations where the macula is not centered on the visual axis
58
When significant angle gamma is present, it can impact the…
Optical placement of IOL during cataract surgery to ensure proper visual correction

Block 5 (46 decks)

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