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WorksheetsOptics 1 Exam 3
Total questions: 102
Worksheet time: 51mins
Name
Class
Date
1.
What is true about prisms?
a)
refract light and change its direction
b)
affects the vergence
c)
surfaces have no dioptric power
d)
refraction at both surfaces (predict via Snell's Law)
e)
Virtual image is displaced toward apex of the prism (light ray bends toward base)
2.
The greater the apex angle the (a) the displacement of the virtual image
3.
When calculating refractions with a prism we assume we are dealing with (a) light.
4.
White light consists of all colors
a)
T
b)
F
5.
Angle of incident and refraction for a prism are defined with respect to (a)
6.
Angle of deviation for a prism is defined with respect to (a) of the incident ray
7.
What is prism power?
a)
quantified in terms of how far light was displaced from the point it would have struck at given distance from prism if not for being bent by the prism
b)
unit is prism diopter (insert triangle here)
c)
quantified in terms of apical angle
d)
quantified in terms of angle of deviation in degrees
8.
A prism that deviates a light ray 1 cm at a distance of one meter has a power of (a) prism diopters
9.
(a) is unit of angular measure whose tangent is 0.01 or 1/100
10.
Prism diopters can be expressed by the equation tan d=P/100 (from tand=x/y)
a)
T
b)
F
11.
What is true about converting from degrees of deviation to prism diopters?
a)
1 degree of deviation produces 1.75 prism diopters
b)
1 prism diopter produces 0.57 degrees of deviations
c)
1 degree of deviation produces 0.57 prism diopters
d)
1 prism diopter produces 1.75 degrees of deviations
12.
What is up with centrad?
a)
seldom-used method of quantifying prism deviation (*upside down triangle)
b)
ray is diplaced 1.0 cm at distance of 1.0m from prism
c)
ray displacement measured on arc of a circle have a 1.0m radius
d)
frequently used clinically
13.
What is true about prism diopter vs centrad?
a)
centrad more consistent unit of measurement but not used clinically
b)
for small angle of prism deviation nearly equal with larger angles become increasing different
c)
prism diopters are a more consistent unit of measurement but rarely used clinically
14.
Image of viewed object is displaced in direction of the (a) of the prism
15.
What is the clinical application of prisms?
a)
fix tropias
b)
fix phorias
c)
fix phobias
16.
When fixing a tropia with a prism the apex of the prism should point (a) the deviation
17.
What is true about splitting prisms?
a)
horizontal prism- split amount of prism in halt. Initial base direction is used for both eyes.
b)
vertical prism- split prism in half. Initial base direction used for eye originally prescribed for, and opposite base direction for other eye.
c)
vertical prism- split amount of prism in halt. Initial base direction is used for both eyes.
d)
horizontal prism- split prism in half. Initial base direction used for eye originally prescribed for, and opposite base direction for other eye.
e)
prevents one of the lenses from being far heavier than the other
18.
Which are matched correctly?
a)
dioptric power- change in vergence of light rays
b)
prismatic power- displacement of image toward prism apex
c)
prismatic power- change in vergence of light rays
d)
dioptric power- displacement of image toward prism apex
19.
What is true about prismatic power?
a)
prismatic power of a lens increases as the distance from the optical center increases
b)
prismatic power of a lens increases as the dioptric power of the lens increases
c)
the greater the prism power, the more the images is displaced (no prismatic power along the optical axis)
20.
For plus lenses base direction corresponds to the (a) direction of decentration
21.
For minus lenses, base direction corresponds to (a) direction of decentration.
22.
What is Prentice's rule?
a)
c (cm)= image displacement
b)
F= absolute power of lens
c)
prism diopters=cF
d)
c= speed of light
23.
Which of the following is a common type of glasses?
a)
single vision for distance or reading
b)
standard bifocal distance/reading
c)
bifocal intermediate/reading
d)
trifocal with distance/intermediate/reading
e)
progressive for distance/intermediate/reading no lines showing (very common)
24.
An absolute prebyope has (a) accommodation left
25.
Part of progressive lenses have areas that are not usable
a)
T
b)
F
26.
The intermediate is usually what percentage of the add?
a)
0.5
b)
0.4
c)
0.6
d)
0.25
27.
The add for a lens results in that area being the add + the distance perscriptions
a)
T
b)
F
28.
What is true about relative size magnification?
a)
achieved by making the object larger while keeping the distance constant (increases angular mag)
b)
RSM=(size of enlarged object)/(size of initial object)
c)
RSM=(original distance from patient to object)/(new distance from patient to object (EVD))
d)
move print/obj/whatever closer
e)
(readable optotype)/(current working distance)=(desired optotype)/(desired working distance (EVD)) aka RSM=RDM
29.
What is true about relative distance magnification?
a)
make print/obj/whatever bigger (increase angular mag)
b)
can run into problems with accommodation
c)
RDM=(original distance from patient to object)/(new distance from patient to object (EVD))
d)
move print/obj/whatever closer
e)
(readable optotype)/(current working distance)=(desired optotype)/(desired working distance (EVD)) aka RSM=RDM
30.
What is true about simple magnifiers (SM)?
a)
F=1/EVD
b)
M=F(q) (1=reference seeing distance)
c)
object should be located at focal length of the plus lens in the magnifier
d)
angular magnification
e)
lateral magnification
31.
EVD=
(a)
32.
What are the types of angular magnification?
a)
Effective magnification
b)
Conventional magnification
c)
Altered magnification
33.
What is up with galilean telescopes?
a)
weak positive objective
b)
strong negative eyepiece
c)
erect image
d)
shorter tube length then keplerian
e)
inverted image
34.
What is up with keplerian telescopes?
a)
weak positive objective
b)
strong positive eyepiece
c)
inverted image
d)
longer tube length than galilean
e)
erect image
35.
What is a terrestrial telescope?
a)
keplerian telescope with inverting lens or prism to produce an erect image
b)
galilean telescope with inverting lens or prism to produce an erect image
36.
What is the equation for angular magnification for telescopes?
a)
M=-Fe/Fo
b)
M=-Fo/Fe
c)
M=Fe/Fo
d)
M=Fo/Fe
37.
What is the equation for tube length?
a)
d=f1+f2
b)
d=f1-f2
c)
d=Fe+Fo
38.
f'2 is (a) for a galilean telescope
39.
F=
a)
(-)n/f
b)
n'/f'
c)
(-n)*f
d)
n'*f'
40.
Keplerian telescopes without an inverting lens are known as
a)
Terresterial
b)
Astronomical
41.
Telescopes are focused for objects at:
(a)
42.
Galilean telescopes have _________ angular magnification and keplerian telescopes have _________ angular magnification
(a)
43.
In galilean telescopes the rays entering and exiting the telescope are in the same order thus they produce an (a) image
44.
In a keplerian telescope rays entering and exiting the telescopes are in reverse order thus they produce an (a) image
45.
For an uncorrected myope using a galilean telescope what is true?
a)
tube length must shorten
b)
magnification will decrease
c)
tube length must increase
d)
magnification will increase
46.
for an uncorrected myope using a keplerian telescope what is true?
a)
tube length must shorten
b)
magnification will decrease
c)
tube length must increase
d)
magnification will increase
47.
For an uncorrected hyperope using a galilean telescope what is true?
a)
tube length must shorten
b)
magnification will decrease
c)
tube length must increase
d)
magnification will increase
48.
for an uncorrected hyperope using a keplerian telescope what is true?
a)
tube length must shorten
b)
magnification will decrease
c)
tube length must increase
d)
magnification will increase
49.
When using a telescope for near viewing distance on must add a _________ to account for the negative vergence of an object not at infinity
a)
reading cap (RC; positive lens)
b)
reading lens (RL; positive lens)
c)
reading cap (RC; negative lens)
d)
reading lens (RL; negative lens)
50.
Reading caps should be treated as a simple magnifier with a neglible distance between it and the objective lens
a)
T
b)
F
51.
Telescopes use (a) magnification
52.
What is true about spectacle/contact lens telescopes?
a)
M=-CLRx/SpRx
b)
M=(CL VA)/ (Sp VA)
c)
are galilean telescopes to prevent upside down images
d)
are used to maximize visual acuities at a distance by turning CL and Sp into a telescope
e)
are keplerian telescopes to prevent upside down images
53.
Hyperopes have better VA when wearing (a) lens
54.
Myopes have better VA when wearing (a) lenses
55.
Range of distances that the object can move while maintaining a clear and single image on the retina
(a)
56.
Range of distances that the images can be placed on the retina while mainting a clear and single image.
(a)
57.
What is true about DOF?
a)
depth of field is conjucated to depth of focus
b)
distances of DOF can be expressed in diopters or linear measures
c)
depth of field=depth of focus when expressed in diopters
d)
depth of field=depth of focus when expressed in linear measures
e)
DOF provides larger ROCV (patients can see farther than FP and closer than NP)
58.
What is true about depth of field?
a)
range in which an object can be resolved
b)
center dioptrically at the distance the eye is focused
c)
conjucated to depth of focus (which is dioptrically cntered on the retina
d)
equals depth of focus when in diopters
e)
range in which an image can be resolved
59.
Angle of deviation produced at the first surface of a prism can be defined as:
a)
B1=θ1-θ'1
b)
B1=θ1+θ'1
60.
The angle of incidence at the second surface of a prism can be defined as:
a)
a=θ'1+θ2
b)
a=θ'1-θ2
61.
The angle of deviation produced at the second surface of a prism can be defined as:
a)
B2=θ'2-θ2
b)
B2=θ'2+θ2
62.
Total deviation of a thick prism can be defined as:
a)
B=B1+B2
b)
B=B1-B2
63.
The angle of deviation can be approximated how and when?
a)
when the apical angle is less than 10
b)
when the apical angle is greater than 10
c)
using d=a(n-1)
d)
using d=a(1-n)
e)
using the dan equation
64.
Tan d=opp/adj=P/100
a)
T
b)
F
65.
What are the overarching types of magnification?
a)
Non-optical
b)
Optical
c)
Linear
d)
Circumvental
66.
What are the types of non-optical magnification?
a)
relative size
b)
relative distance
c)
lateral
d)
angular
e)
effective
67.
What are the types of optical magnification?
a)
lateral
b)
angular
c)
effective
d)
conventional
e)
relative
68.
Which of the following are most relevant to the clinical condition of low vision?
a)
Lateral (transverse or linear)
b)
Size
c)
Relative distance
d)
angular
e)
effective and conventional
69.
Which of the following are most relevant to the clinical condition Aniseikonia?
a)
Spectacle
b)
Size
c)
Relative distance
d)
angular
e)
effective and conventional
70.
Magnification used when the object is within the focal length of a plus lens, thereby creating a virtual image.
a)
Lateral (transverse or linear)
b)
Size
c)
Relative distance
d)
angular
e)
effective and conventional
71.
Magification used when the object is made physically larger
a)
Lateral (transverse or linear)
b)
Size
c)
Relative distance
d)
angular
e)
effective and conventional
72.
Magnification used when the object is moved physically closer to the eye
a)
Lateral (transverse or linear)
b)
Size
c)
Relative distance
d)
angular
e)
effective and conventional
73.
Magnification used when the angle an object makes at the eye is increased
a)
Lateral (transverse or linear)
b)
Size
c)
Relative distance
d)
angular
e)
effective and conventional
74.
Magification used when a manufacturer labels plus lenses to allow consumers to compare their magnifications (clinicians convert this value to a dioptic value)
a)
Lateral (transverse or linear)
b)
Size
c)
Relative distance
d)
angular
e)
effective and conventional
75.
Magnification used for when a patient has anisometropia and the correcting spectacle lenses create images of different angular sizes for the two eyes
a)
spectacle
b)
Size
c)
Relative distance
d)
angular
e)
effective and conventional
76.
You can specify print size by acuity or optotype thus what are some examples of M notation?
a)
1M subtends 5' of arc at 1 meter
b)
a 20/20 Snell acuity chart letter subtends 5' of arc at 20 ft
c)
1M is equal to 20/20 at 1 meter
d)
1M size is 1.45 mm high
e)
1M= 20/50 reduced Snell acuity (newspaper print)
77.
What is true about lateral magnification?
a)
M=L/L'=h'/h or M=l'/l when surround by one medium
b)
aka transerve or linear magnification
c)
when obj @ infinity M=0 (telescope mag)
d)
when obj @ focal point M=0 (image@infinity)
e)
incredibly useful for telescopes and when obj at focal pt
78.
What is true about angular magnification?
a)
compare the angular size of object unmagnified to angular size of the object through the lens
b)
need to know object distance from the eye (handheld assume obj at f of lens)
c)
object will be q (equals fe+distance of lens from eye)
d)
Mag=Fe*q
e)
Mag=Fe/q
79.
q is referred to as "reference seeing distance" or RSD and is part of tan(i)=h/q
a)
T
b)
F
80.
Equivalent viewing power can be written as
(a)
81.
Distance between the eye and the hand held magnifier matters when the object is at the fe (EVD)
a)
T
b)
F
82.
When using a hand-held magnifier, should a bifocal wearer look through the distance or near portion of the lens to get the most magnification?
a)
if a magnifier is held at its focal length the equivalent power of the system is equal to the power of the magnifier (can look through the distance or bifocal add)
b)
if the separation between the magnifier and the glasses is less than the focal length of the magnifier there is an increase in power (so you can use the add)
c)
if the separation between the magnifier and the glasses is greater than the focal length of the magnifier there is a decrease in power (don't look through add)
d)
Fe=Fm+Fa-(distance between magnifier and add)*Fm*Fa
83.
What is true about effective magnification?
a)
nominal magnification
b)
type of angular mag that chooses a specific RSD to use as a standard for quantifying plus lenses or lens systems
c)
q= either 25 or 40cm
d)
conventional mag=1+Fe/4
e)
works on the underlying assumption patient supplies 1 unit (1x) of magnification
84.
What is true about convention magnification/trade magnification?
a)
conventional mag=1+Fe/4
b)
works on the underlying assumption patient supplies 1 unit (1x) of magnification
c)
nominal magnification
d)
type of angular mag that chooses a specific RSD to use as a standard for quantifying plus lenses or lens systems
e)
q= either 25 or 40cm
85.
How does uncorrected ametropia influence magnification?
a)
total Mag=(power of magnifier-power of lens to correct eye)/4 (assuming q=25cm and holding magnifier in spectacle plane)
b)
uncorrected myope has increased magnification
c)
uncorrected hyperope has decreased magnification
d)
uncorrected hyperope has increased magnification
e)
uncorrected myope has decreased magnification
86.
What is true about magnification using a lens magnifier?
a)
object closer than focal length of plus lens
b)
lateral magnification with an enlarged virtual image
c)
working distance is image to eye and the patient must accommodate or use add
d)
object distance is length of stand legs
e)
Mlateral=L/L'
87.
What is true about magnification using CCTV?
a)
both optotype and specific viewing distance are required
b)
(readable optotype size)/(current viewing distance)=(Required M)*(desired optotype size)/(desired viewing distance) (also good for lateral magnification)
c)
(readable optotype size)*(current viewing distance)=(Required M)/(desired optotype size)*(desired viewing distance) (also good for lateral magnification)
88.
Which of the following are equations for effective magnification?
a)
M25=Fe/4
b)
M40=Fe/2.5
c)
M40=Fe/4
d)
M40=Fe/2.5
89.
Which equations are matched up properly?
a)
Reading cap magnification=F*q
b)
Reading cap power=-1/WD
c)
Total magnification=MRC*Mtelescope
90.
Compared the the keplarian telescope galilean telescopes:
a)
longer tube length
b)
straight shape
c)
generally lighter
d)
less field of view
e)
exit pupil outside the tube
91.
When wearing spectacles, who has to accommodate the most?
a)
Hyperopes
b)
Myopes
c)
Emmetropes
92.
Myopes have to accommodate more in:
(a)
93.
Hyperopes have to accommodate more in:
(a)
94.
Amount of accommodation required to see clearly at near with glasses on depends on:
a)
Distance from the lens to cornea (vertex distance)
b)
Power of the distance spectacle lens
c)
Near viewing (working) distance
d)
Distance viewing (working) distance
95.
When wearing spectacle lenses, accommodation required:
a)
Hyperope > emmetrope > myope
b)
Hyperope requires a bifocal or progressive first
c)
Hyperope = emmetrope = myope
d)
All require bifocal or progressive at about the same time
96.
When wearing contact lenses, accommodation required:
a)
Hyperope > emmetrope > myope
b)
Hyperope requires a bifocal or progressive first
c)
Hyperope = emmetrope = myope
d)
All require bifocal or progressive at about the same time
97.
Why do middle-aged myopes sometimes have trouble with reading when switching into contact lenses, but middle- aged hyperopes do not?
a)
Myopes have to accommodate more in CL than their Specs
b)
Hyperopes have to accommodate less in CL than their Specs
c)
Hyperopes have to accommodate more in CL than their Specs
d)
Myopes have to accommodate less in CL than their Specs
98.
Why do some previous spectacle lens-wearing myopes have trouble with reading after undergoing refractive surgery?
a)
Myopes have to accommodate more with the correction at the corneal plane, so in CL and after refractive surgery
b)
Myopes have to accommodate less with the correction at the corneal plane, so in CL and after refractive surgery
99.
Typical trifocal is (a) % of bifocal power
100.
Prescribe trifocal when there is an intermediate distance that is not clear through the distance or near portion of the lens
a)
T
b)
F
101.
What is up with hyperfocal distance?
a)
nearest distance the eye/camera can be focused and still resolve infinitely distant objects
b)
distance where the farthest extent of the depth of field is infinity
c)
tells you where to focus camera to have widest range of clear vision or images thus determining the needed lens to focus camera
d)
half the total depth of field in dioptric units and then converted to linear measure
102.
Which of the following is the equation for angle of refraction for a thin prism?
a)
angle of refraction=d+a
b)
angle of refraction=d-a
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