What Limits Vision Flashcards

(31 cards)

1
Q

What is the limit of human retina

A

300 pixels/inch

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

Which PSF corresponds to a small pupil?

A

Large airy disc

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

Between vision is achieved with
A. With a more confined PSF
B. With a less confined PSF
C. PSF size doesn’t matter

A

With a more confined PSF

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

The we consider diffraction only, better vision is achieved with

A

Larger pupil

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

PSF without aberrations would be what

A

Airy disc

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

Aberrations and pupil size

A

Get worse with larger pupil

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

Larger pupil with diffraction only

A

Increased VA

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

Aberrations and pupil size

A

Worse with larger pupil

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

What is the sweet spot for diffraction and aberration

A

2-3mm pupil

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

Pupil-dependent limit to vision

A

About 1 arcmin

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

What is not taken into consideration when talking about retinal display

A

Viewing display

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

The required pixel density to meet the criterion for retinal display

A

Varies depending on size of display

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

What kind of screen has potential to be a retinal display?

A

Any if at the right distance

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

Resolution limit for the standard vision human eye

A

1 arcmin

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

Pixel density for retinal display

A

1 pixel per 88microns, over an inch, 288 pixels make it 300

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

What part of the eye os responsible for image formation?

A

Cornea, lens, pupil

Aberrations and diffraction

17
Q

Image collection and recording in eye

A

Retina (photoreceptors)

18
Q

What is the average cone spacing in fovea

A

2.6microns, 0.5 arcmin

19
Q

Cone spacing

A

Rods and cones behave differently and aren’t dispersed evenly

20
Q

With half the photosensor pixel size, resolution is

21
Q

What signal do we perceive

22
Q

What signal do we send to the brain

23
Q

Limitations imposed by cone signaling

A

If the signal has more dense info, this wont be picked up

Sensor spacing=cone spacing (fovea)

24
Q

Digital sampling limit to vision

25
What do you control with pinhole
Depth of field
26
What are the two jobs of pinhole
1. Sweet spot | 2. Increase depth of focus
27
What does pinhole ultimately do
Aberration and diffraction still there, but all these effects are least possible with pinhole
28
What does pinhole visual rule out
Pathology
29
Diffraction effects due to a small pinhole contribute to what
- Increase of the size of the circle of least confusion - increases the range of acceptable vision (depth of focus) - reduces effects of aberrations
30
Pinhole occluder said with a _____ aperture are used during routine ocular examination to benchmark the potential for best refractive visual correction
1.2mm
31
The pinhole allows individuals with a refractive error up to _______ to see up to ______ logMar
5 diopter | 0.17 logMAR