Visual Acuity And Emmetropia

Question 1

Clarity or sharpness of vision

Answer 1

Resolution ability

Question 2

What does resolution ability rely on

Answer 2

How close two targets are and the target distance from the eye

Question 3

What is the best unit to use to resolution ability

Answer 3

Angle units

Question 4

What units do we usually use in physics

Answer 4

Radians

Question 5

What units do we usually use in real world

Answer 5

Degrees

Question 6

What units does optometry usually work with

Answer 6

Arcminutes

Question 7

What field utilizes arcseconds

Answer 7

Astronomy

Question 8

To convert from radians to degrees

Answer 8

Multiply 180/pi

To get arc seconds, take the answer and divide by 60

Question 9

To convert from degrees to radians

Answer 9

Multiple by pi/180

Question 10

Can we see to infinity?

Answer 10

Yes

Question 11

What limits our vision?

Answer 11

We can see to infinity but limited by poor eyesight that inhibits detail

Question 12

How can we best express the separation of two stars

Answer 12

Arcsec

Question 13

When something appears larger or smaller depending on how close it is to us, what do we actually see

Answer 13

Angular size

Question 14

Apparent viewing angle

Answer 14

= target size (h)/target distance (d)

You will get the answer in radians, make sure to convert to arc minutes

Question 15

The smaller angular separation of two distinct resolvable points

Answer 15

Minimum angle of resolution (MAR)

Question 16

What is being determined in VA?

Answer 16

Minimum angle of resolution (MAR)

Smallest is better

Question 17

What is the resolving power ability?

Answer 17

The reciprocal of the minimum angle of resolution (MAR)

Bigger the better

Question 18

The separation (expressed either angularly or spatially) between the closest distinguishable image points

Answer 18

Resolution limit

Question 19

The smaller the better

Answer 19

Resolution limit

Question 20

Expressed in angle (arcminute, arc second) or length units

Answer 20

The reciprocal of the separation between the closest distinguishable points imaged through an optical instrument

Question 21

Resolving power (ability)

Answer 21

The larger the better

Question 22

Resolving power (ability)

Answer 22

Is expressed in inverse angle (arcmin-1) or inverse length (lines/mm, closes/degree)

Question 23

How do you calculate VA?

Answer 23

1/MAR

Make sure MAR is in arcminutes

Question 24

What is VA

Answer 24

Not about how far two resolvable objects are

It’s about how small their angular separation is

Question 25

The smaller the MAR, the

Answer 25

Better the VA

Question 26

In a corrected eye, what causes blur

Answer 26

Diffraction and abberations

Question 27

Larger the pupil diameter

Answer 27

The finer the PSF

Question 28

A more confined PSF is achieved with

Answer 28

A larger pupil

Question 29

The optical system is only limited by diffraction. Only in very good systems such as out eyes

Answer 29

Diffraction-limited

Question 30

Which of the following is a diffraction-limited PSF?

Answer 30

A perfect cone looking thing

Question 31

Is a finer or broader PSF better?

Answer 31

Finer

Question 32

Better vision is achieved with

Answer 32

With a more confined PSF

Question 33

Parks separated by the angular radius

Answer 33

Angular separation

Question 34

Can we magnify the image to get better resolution?

Answer 34

When two image spots overlap, it does not help any further to magnify the formed image. They will still be overlapping! The spots are either resolved or not

Question 35

Which of the following can be parametrized?

Answer 35

Lambda=0.55 microns | D=2mm

Question 36

Human eye minimum angle of resolution (diffraction limit)

Answer 36

1 arcminute

Question 37

Which of the following can be parametrized? A. Wavelength B. RI C. Pupil diameter

Answer 37

A and C

Question 38

The greater the MAR, the ____ the VA

Answer 38

Less

Question 39

The less the MAR, the _____ the VA

Answer 39

Greater

Question 40

Small diameter pupil= _______ MAR in diffraction limited scenario

Answer 40

Large

Question 41

Best VA in ____ pupil in diffraction limited scenario

Answer 41

Larger

Question 42

Under dim light, resolution is better in diffraction limited system?

Answer 42

True

Question 43

Diameter of telescope lenses

Answer 43

Larger because in diffraction limited system, larger pupil=smaller MAR (better VA)

Question 44

Dependence of MAR on pupil diameter. Combined effect of diffraction and abberations

Answer 44

Pinhole is based on this