Brainscape's Knowledge GenomeTM

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


See full index

Optics Theory > Year 1 Optics > Flashcards

Year 1 Optics Flashcards

1
Q

What is a equal to apical angle in Prentice Position?

A

i2

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

What is equal to apical angle in Frontal Position?

A

i1

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

What is equal to apical angle in Minimum Angle of Resolution? Are there any other equations we should know?

A

2i1’
i2’ = i1
i1’ = i2

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

What is the eV equation?

A

eV = Joules/e

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

What is Joules equivalent to?

A

DeltaE

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

What is the minimum angle of resolution equation?

A

Angle in seconds that it subtends by divided by the no. of units in the letter (usually 5 units)

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

How do we convert Snellen to logMAR?

A

E.g. 6/12 would be 12/6 = 2
log2 = 0.3 logMAR

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

How do we convert logMAR to Snellen?

A

Reverselog0.3 = MAR
MAR x5 = Total angle subtended
MAR x6 = Snellen Equivalent

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

What path does light travel along in relation to time?

A

The path of least time

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

How is frequency measured?

A

In the number of vibrations per second measured in Hertz or ‘cps’

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

What are the abbreviations for Speed?

A

C (in a vacuum)
V (not in a vaccum)

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

What is wavelength?

A

The gap between 2 troughs or 2 peaks

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

How is wavelength measured?

A

In nanometers (10 to the power of -9)

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

What is the constant of speed of light in vacuo?

A

3 x10 to the power of 8

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

What is the visible light wavelength range?

A

400 - 700nm

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

What is the equation for speed?

A

Speed = Wavelength x Frequency

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

How do we work out nmedium?

A

nmedium = speed in vacuo/speed in medium

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

Define refractive index

A

Speed of the ray as it changes as it passes from one to another which gives us refractive index

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

Where does light deviate in a prism?

A

Towards the base (image deviates towards the apex)

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

When going rare to dense, what direction does the light deviate?

A

Towards the normal

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

In parallel sided blocks what does i1’ = i2 mean?

A

Angle of refraction at the 1st surface is equal to the angle of incidence at the 2nd surface

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

What’s the formula for DTOT?

A

(i2’ + i1) - a (i1’ + i2)

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

What is the DTOT formula for then apical angle is equal to or <10PD?

A

a(n-1)

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

What is the equation for Curvature?

A

Curvature = 1/radius of curvature

R = 1/r

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

What do we measure instead of the angle of incident of a curved surface?

A

Measure the radius (r) from surface of object point and then from surface to the image point

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

What is L’?

A

Image vergence (curvature of light wavefront leaving the focal surface or lens)

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

What is L?

A

Object vergence

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

What is Fsurf?

A

Measures how much the object changes the object vergence

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

What relationship is there between object distance and image distance and object and image vergence?

A

Inverse relationship so when object distance is closer there is a larger vergence

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

What relationship is there between rsurf and Fsurf?

A

Inverse relationship between radius of curvature of a focal surface and the focal power of a surface

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

If it’s a real object what is a minus number?

A

l (little L)

32
Q

What does a convex surface mean for figures?

A

That r (radius of curvature) is a positive value

33
Q

What does a concave surface mean for figures?

A

That r (radius of curvature) is a negative value

34
Q

How many outcomes are there for a real object adding curvature?

A

1) Image vergence is converging
2) Image vergence is diverging
3) image vergence is zero

35
Q

If a real object, adding divergence = one outcome which is what?

A

Image vergence is diverging

36
Q

How do we work out first and second focal lengths in a curved surface?

A

f = n/-Fsurf
f’ = neye/Fsurf

37
Q

How do we work out first and second focal lengths in thin lenses?

A

f = 1/-Fsurf

f’ = 1/Fsurf

38
Q

How do we know if an image is erect?

A

h’ will be positive

39
Q

How do we know if an image is magnified?

A

h’ > h
Or do h’/h and if higher than 1 then it’s magnified

40
Q

What does it mean if the image is <1 in magnification?

A

It means it’s not magnified but is minified

41
Q

What does it mean if l is before f on the axis (closer to surface)?

A

Virtual image

42
Q

How to work out tanW?

A

h’ / l’ - r

43
Q

How do we work out Flens in thin lenses?

A

F1 + F2

F1 = nlens - 1 / r1

F2 = 1 - nlens / r2

44
Q

How do we work out F1 in thin lenses?

A

nlens - 1 / r1

45
Q

How do we work out F2 in thin lenses?

A

1 - nlens / r2

46
Q

If we have a strong lens, what do we not have to do as much in glasses?

A

If a strong lens (Flens) we don’t have to decentre (c) as much as cFlens

47
Q

What is neye’s value?

A

1.333

48
Q

What is f’eye?

A

Calculation of where the retina needs to be for this model eye to be focused for looking at the object at optical infinity. Where the retina needs to be looking at optical infinity.

49
Q

What is conjugate focus?

A

Means there’s a special relationship so will form an image at some point (B & B’). This is a retinal conjugate with the optical reversibility of light

50
Q

If Feye is >+60D then what needs to be smaller to remain emmetropic?

A

f’eye

51
Q

If Feye is <+60D then what does f’eye need to be?

A

Larger to account for Feye being smaller

52
Q

When is an eye considered emmetropic?

A

When f’eye and Feye are satisfied

53
Q

What is under active control?

A

f’eye

54
Q

What is the distance from the anterior corneal surface to retina?

A

Axial length (k’)

55
Q

What is k?

A

Distance to retinal conjugate / far point

56
Q

What is K’?

A

Axial length in D
Represents required vergence for light to image on the retina

57
Q

What is K?

A

Ocular refraction. Error between optical power and eye size.

58
Q

What is Ametropia?

A

Not Emmetropia

59
Q

When is someone considered Myopic?

A

When Feye > K’
or
f’eye < k’

60
Q

When is someone considered Hypermetropic?

A

When Feye < K’
or
f’eye > k’

61
Q

Where is the retinal conjugate of a myope?

A

Is in real object space when accommodation is relaxed.

No incident ray parallel to optical axis so light comes out converging in a myope.

k (retinal conjugate) is in real space as a minus value

62
Q

Where is the retinal conjugate of a hyperopic?

A

Is in virtual space when accommodation is relaxed so beyond measure of the eyes

No incident ray parallel to optical axis so light comes out diverging in a hypermetrope

k (retinal conjugate) is a plus so is in virtual object space

63
Q

What is diffraction?

A

Waves coming in straight bend around an edge. This happens around the edge and are propagated out but get cancelled before this; the surface acts as another light source

64
Q

What type of light needs to be used to show diffraction?

A

Monochromatic

65
Q

When do we get interference?

A

If 2 wavelengths are of the same speed with max and min displacements in time with each other we get interference

66
Q

What is ‘Constructive Interference’?

A

When in-phase wavelengths increase the maximum amplitude (sum of the two)

67
Q

What is ‘Destructive Interference’?

A

When the waves are 180 degrees out of phase of each other; the positive direction of one matches negative direction wavelength of another so they cancel each other out

68
Q

When light travels from rare to dense medium, what happens to the reflected light?

A

Undergoes a “phase change” equal to 180 degrees so reflected light is also polarised if the wave is transverse

69
Q

What is polarisation?

A

Due to vibrations of the electrical and magnetic fields being perpendicular to the direction of propagation, they need to be perpendicular to each other

70
Q

What is polarisation EVIDENCE of?

A

Evidence of a transverse wave

71
Q

What is wave nature shown by?

A

Dispersion
Diffraction
Interference
Polarisation

72
Q

In a thin lens, if f’ is a minus number, what does it mean?

A

That the light is diverging

73
Q

In a thin lens, if f is a minus number, what does this mean?

A

That the light is converging

74
Q

What does it mean for Fsp to always be more negative than K?

A

Spectacle correction is always more negative than ocular refraction

75
Q

What are we doing when we place a correcting lens?

A

Making the 2nd focal point of the correcting lens coincide with the far point (k) of the eye

76
Q

In contact lenses what is K = 1/k equal to?

A

Fcl = 1 / f’cl

Optics Theory (1 decks)

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