Midterm 2 Making up Test Items by John Mark Jackson https://padlet.com/jmjackson/midterm2 Make up your own exam question, with stem, choices, and correct answer! en-us 2017-10-23 04:02:10 UTC 2017-10-27 14:58:07 UTC hello@padlet.com Dr. J example jmjackson https://padlet.com/jmjackson/midterm2/wish/199438949 How much prism is induced when looking 4mm away from the center of a +5D lens?
a. 1PD
*b. 2PD
c. 3 PD
d. 4 PD]]> 2017-10-23 04:05:11 UTC https://padlet.com/jmjackson/midterm2/wish/199438949 Team 18A https://padlet.com/jmjackson/midterm2/wish/200450173 A patient looks through the bottom half of a minus lens. What prism is induced?
a. Base up
*b. Base down
c. Base in
d. Base out

Dr. J: good. Be sure you can calculate how much (Prentice's rule)]]> 2017-10-25 15:07:31 UTC https://padlet.com/jmjackson/midterm2/wish/200450173 https://padlet.com/jmjackson/midterm2/wish/200450222 Team 8A]]> 2017-10-25 15:07:39 UTC https://padlet.com/jmjackson/midterm2/wish/200450222 Team 15: B https://padlet.com/jmjackson/midterm2/wish/200450251 If the index of the cornea is 1.376,  an effective gonioscopy lens could have an index of..
a. 1.276
b. 1.137
c. 1.255
*d.1.567

Dr. J: good one...a little bit of a thinker.]]> 2017-10-25 15:07:42 UTC https://padlet.com/jmjackson/midterm2/wish/200450251 Team 16B https://padlet.com/jmjackson/midterm2/wish/200450263 What is the critical angle for an interface if the incident medium has an index of 1 and the emergent medium has an index of 1.49?
A. 42.16•
B. 2.6•
*C. There is no critical angle. 
D. 90•

Dr. J: good]]> 2017-10-25 15:07:43 UTC https://padlet.com/jmjackson/midterm2/wish/200450263 Team 21a https://padlet.com/jmjackson/midterm2/wish/200450273 You are a myope, gasp! While wearing your best correction glasses, you look up towards the top of your lenses. What kind of prism are you looking through?

a. Base Out
b. Base Down
c. Base Up*
d. Base In

dr. J: to be clear: an eye can BE myopic; a person can HAVE myopia]]> 2017-10-25 15:07:44 UTC https://padlet.com/jmjackson/midterm2/wish/200450273 Team 20A https://padlet.com/jmjackson/midterm2/wish/200450290 Diverging light is 3meters away from a +20 lens and a -10D that are separated by 30cm. If a screen is 1 meter away will an image be formed on it? 

A. Yes
B. No*

Dr. J: so where will the image be formed? What kind of image is formed?]]> 2017-10-25 15:07:46 UTC https://padlet.com/jmjackson/midterm2/wish/200450290 Team 10a https://padlet.com/jmjackson/midterm2/wish/200450297 What is the critical angle for glass (n=1.52) to water (n= 1.33) interchange? 
A. 90 degrees
B. 52 degrees
*C. 61 degrees
D. No critical angle 

Dr. J: good]]> 2017-10-25 15:07:46 UTC https://padlet.com/jmjackson/midterm2/wish/200450297 Team 17a https://padlet.com/jmjackson/midterm2/wish/200450326 If you increase the thicknesses of a biconcave lens, how will the back vertex power change?

A. More negative
*B.  More plus
C. No change in power]]> 2017-10-25 15:07:48 UTC https://padlet.com/jmjackson/midterm2/wish/200450326 https://padlet.com/jmjackson/midterm2/wish/200450328 Team 9b

True or false: The light ray is always deviated towards the apex of the prism. 

False: the light is deviated toward the base, the image appears to move in the direction of the apex

Dr. J: good]]> 2017-10-25 15:07:49 UTC https://padlet.com/jmjackson/midterm2/wish/200450328 Team 12a https://padlet.com/jmjackson/midterm2/wish/200450360 If you have minus vergence going into a plus lens and plus vergence leaving the lens, you will have an inverted image.

*A. True
B. False

Dr.J: true, but this doesn't really hit on a 2nd midterm topic per se. You need to know this, but could tailor this more to thick lenses?]]> 2017-10-25 15:07:52 UTC https://padlet.com/jmjackson/midterm2/wish/200450360 Team 19A https://padlet.com/jmjackson/midterm2/wish/200450362 If you have 4 prism diopters Base up in OD and 3 prism diopters Base down in OS, what is the net prism effect?

  1. 1 prism D BU OS
  2. 1 prism D BU OD
  3. 7 prism D BU OD **
  4. 5 prism D BO OD
 
]]> 2017-10-25 15:07:52 UTC https://padlet.com/jmjackson/midterm2/wish/200450362 Team 14a https://padlet.com/jmjackson/midterm2/wish/200450368 Two 5 prism diopter prisms are at 40 degrees and 140 degrees over OD. What is the net prism power and base direction? 

*A. 6.43 prism diopters BU
B. 5 prism diopters BD
C. 7.66  prism diopters BU
D. 2.5 prism diopters BU]]> 2017-10-25 15:07:53 UTC https://padlet.com/jmjackson/midterm2/wish/200450368 Team 22b https://padlet.com/jmjackson/midterm2/wish/200450381 Patient needs 4 BI and 6 BD over the OS. Resultant single prism power?
A. 6.4 prism
B. 5.8 prism
C. 7.2 prism***
D. 7.8 prism

Dr. J: good]]> 2017-10-25 15:07:55 UTC https://padlet.com/jmjackson/midterm2/wish/200450381 Team 23B https://padlet.com/jmjackson/midterm2/wish/200450393 What is the add power for a bifocal lens with the following powers:
Power through the top with back against the stop: -4
Power through the bifocal with the back against the stop: -2.50
Power through the top with the front against the stop: -5
Power through the bifocal with the front against the stop: -3

A: +1.50
B: +2.00*
C: +1.00
D: +0.50

]]> 2017-10-25 15:07:56 UTC https://padlet.com/jmjackson/midterm2/wish/200450393 https://padlet.com/jmjackson/midterm2/wish/200450397 Team 4B (GOAT)

If the parallel rays coming from the Death Star’s laser passed through a 5cm thick lens (n = 1.6) with a front surface power of +5.00 and a back surface power of +4.00, will the laser beam converge on a planet 15 cm away?

A. Annihilated
B. Not annihilated *

dr. J: seriously?
And, did you mean front and back surface powers or vertex powers? I think you mean surface powers.]]> 2017-10-25 15:07:56 UTC https://padlet.com/jmjackson/midterm2/wish/200450397 Team 20b https://padlet.com/jmjackson/midterm2/wish/200450401 What determines cardinal points/planes? 
a. Lens shape
b. Object distance
c. Index of refraction of the lens
d. Back vertex power
e. a & b
*f. a & c
g. c & d]]> 2017-10-25 15:07:57 UTC https://padlet.com/jmjackson/midterm2/wish/200450401 Team 7A https://padlet.com/jmjackson/midterm2/wish/200450431 A lens has a front surface with a positive radius of curvature and a back surface with a negative radius of curvature.  What is the shape of this lens?

A. Biconcave
B. Biconvex *
C. Concave meniscus
D. Convex meniscus
E. Circle]]> 2017-10-25 15:08:00 UTC https://padlet.com/jmjackson/midterm2/wish/200450431 Team 2b https://padlet.com/jmjackson/midterm2/wish/200450433 2017-10-25 15:08:00 UTC https://padlet.com/jmjackson/midterm2/wish/200450433 Team 9a https://padlet.com/jmjackson/midterm2/wish/200450468 If light is entering a convex surface from a dense to rare medium, will the power be (+), (-) or 0?
A. (+)
*B. (-)
C. 0

Dr. J: good]]> 2017-10-25 15:08:03 UTC https://padlet.com/jmjackson/midterm2/wish/200450468 Team 6b https://padlet.com/jmjackson/midterm2/wish/200450485 If a patient is reading a book up close through minus lenses and the optical center is in the middle of the lens, what kind of prism are they looking through?
A. OD-BO/OS-BO
B. OD-BI/OS-BI***
C. OD-BO/OD-BI
D. OD-BI/OD-BO

]]> 2017-10-25 15:08:05 UTC https://padlet.com/jmjackson/midterm2/wish/200450485 Team 8b https://padlet.com/jmjackson/midterm2/wish/200450502 Going from air, which medium would bend light closest to the normal line?
a. Water
b. Plastic
*c. Crown glass
d. air

Dr. J: There are a number of plastic materials with different indexes, so would need to specify which one. CR-39? Polycarbonate? I'll give indexes of lens materials if you need to know.]]> 2017-10-25 15:08:06 UTC https://padlet.com/jmjackson/midterm2/wish/200450502 Team 10b https://padlet.com/jmjackson/midterm2/wish/200450526 2017-10-25 15:08:07 UTC https://padlet.com/jmjackson/midterm2/wish/200450526 Team 6 A https://padlet.com/jmjackson/midterm2/wish/200450536 The front surface of a thick lens is +8 and the back surface is -1. The thickness is 5 cm and the index of the lens is 1.68. What is the equivalent power? And what lens shape is this? 

A: +7.24, concave meniscus
*B: +7.24, convex meniscus 
C: +6.76, convex meniscus
D: 6.76, biconvex 

]]> 2017-10-25 15:08:08 UTC https://padlet.com/jmjackson/midterm2/wish/200450536 Team 1a https://padlet.com/jmjackson/midterm2/wish/200450566 What horizontal and vertical prisms combine to give 3 prism diopters at 280 degrees over the OS?

1. 0.8 BO and 3.2 BD
2. 0.53 BO and 2.95 BD*
3. 0.25 BO and 3.45 BD
4. 1.5 BO and 1.5 BD]]> 2017-10-25 15:08:12 UTC https://padlet.com/jmjackson/midterm2/wish/200450566 14b https://padlet.com/jmjackson/midterm2/wish/200450579 True or false- you can have total internal reflection from both rare to dense or dense to rare mediums. 
A-true
*B-false

dr. J: good]]> 2017-10-25 15:08:13 UTC https://padlet.com/jmjackson/midterm2/wish/200450579 Team 19b https://padlet.com/jmjackson/midterm2/wish/200450585 A 2 cm thick lens (n=1.5) has a front surface power of +4 and a back surface power of -2 what is the equivalent power of the lens?
A. +3
B.+1.89
*C.+2.12
D. +2.53

Dr. J: good]]> 2017-10-25 15:08:13 UTC https://padlet.com/jmjackson/midterm2/wish/200450585 Team 1B https://padlet.com/jmjackson/midterm2/wish/200450588 Risley prisms are adjusted with one base at 135 degrees and the other at 225 degrees over the OS. What is the resultant base direction? 
A. BI**
B. BO
C. BU
D. BD

Dr. J comment: good]]> 2017-10-25 15:08:13 UTC https://padlet.com/jmjackson/midterm2/wish/200450588 Team 17b https://padlet.com/jmjackson/midterm2/wish/200450593 when light is going into a meniscus (with + r values) going from rare to dense and exiting to an more dense material, which surface power would be more plus?

A. F1
B. F2** 

Dr. J: I don't think you have enough information to answer. They would both be plus powers, but without knowing the radii or the indexes I don't see how you could pick one. Am I missing your point?]]> 2017-10-25 15:08:14 UTC https://padlet.com/jmjackson/midterm2/wish/200450593 Team 13a https://padlet.com/jmjackson/midterm2/wish/200450655 Decreasing the thickness of a concave meniscus lens will make the lens: 
A. More plus
*B. More minus
C. Less minus
D. No change

Dr. J: good]]> 2017-10-25 15:08:21 UTC https://padlet.com/jmjackson/midterm2/wish/200450655 Team 15A https://padlet.com/jmjackson/midterm2/wish/200450680 2017-10-25 15:08:24 UTC https://padlet.com/jmjackson/midterm2/wish/200450680 Team 11 B https://padlet.com/jmjackson/midterm2/wish/200450687 What would happen to a minus lens if you increase the lens thickness? 

**A) less minus 
B) stays the same 
C) more minus 
D) depends on where the object is located 

Dr. J: good]]> 2017-10-25 15:08:24 UTC https://padlet.com/jmjackson/midterm2/wish/200450687 Team 3 https://padlet.com/jmjackson/midterm2/wish/200450756 When determining the lateral magnification it a multi lens system, you divide the object vergence by the final image vergence?! 
A. True
B. False
C. I give up 

Dr. J: a little unclear in the stem. You could say L of lens 1 divided by L' of lens 2 to be clearer? You didn't put what you think is the answer, but it should be false.

]]> 2017-10-25 15:08:31 UTC https://padlet.com/jmjackson/midterm2/wish/200450756 Team 22a https://padlet.com/jmjackson/midterm2/wish/200450758 Moving from a dense to rare medium, how does the ray bend?

*A. Away from the normal line
B. Toward the normal line
C. It doesn’t 

Dr.J: good]]> 2017-10-25 15:08:31 UTC https://padlet.com/jmjackson/midterm2/wish/200450758 Team 4A https://padlet.com/jmjackson/midterm2/wish/200450804 As light goes from a dense to a rare medium through a convex surface, what power does the surface have?
A. Plus power
B. Minus power (correct)
C. Electric power
D. Horsepower 

dr. J: good]]> 2017-10-25 15:08:33 UTC https://padlet.com/jmjackson/midterm2/wish/200450804 https://padlet.com/jmjackson/midterm2/wish/200450808 Team 2A
If you have a 1cm lens (n=1.5) with a front surface power of +3.00D and back surface power of +8.00D, what is the equivalent power of the lens?
A. 11.00D
B. 10.50D
C. 23.93D
D. 10.84D*

Dr. J: good

]]> 2017-10-25 15:08:33 UTC https://padlet.com/jmjackson/midterm2/wish/200450808 Team23a https://padlet.com/jmjackson/midterm2/wish/200450873 What is the Fe for a lens that has a front surface power of +7D,  back surface power of -2D, thickness of 2mm and n=1.5

1) 5.01**
2)5.19
3) 4.81
4)4.98

dr. J: good, but would round to 5.02 :-) 2mm isn't especially thick either as the result would indicate]]> 2017-10-25 15:08:40 UTC https://padlet.com/jmjackson/midterm2/wish/200450873 Team 5B https://padlet.com/jmjackson/midterm2/wish/200450937 which radius is longer in a concave meniscus lens? 
A. Front radius *
B. Back radius
C. Same length 
D. Panic 

Dr. J: good]]> 2017-10-25 15:08:44 UTC https://padlet.com/jmjackson/midterm2/wish/200450937 Team 5A https://padlet.com/jmjackson/midterm2/wish/200450953 For a convex meniscus lens, what part of the lens has a shorter radius of curvature?
*A) Front Surface
B)Principal Plane
C) Back Surface
D)It's the same throughout the lens

Dr. J: good]]> 2017-10-25 15:08:46 UTC https://padlet.com/jmjackson/midterm2/wish/200450953 Team 13b https://padlet.com/jmjackson/midterm2/wish/200450975 For a plus lens with a power of 4D, what is the furthest the object can be away from the lens while still creating an upright image? 
*A. -24 cm
B. +24 cm
C. +26 cm
D. -26 cm

Dr. J comment: for a real object, the object has to be closer than -25cm. But for ANY virtual object, you would have an upright image, too.]]> 2017-10-25 15:08:49 UTC https://padlet.com/jmjackson/midterm2/wish/200450975 Team 11a https://padlet.com/jmjackson/midterm2/wish/200451081 How does the power of a biconcave lenschange as the Lena gets thinner?

A. Gets more plus
*B. Gets more minus
C. Stays the same 
D. Induces more prism

Dr. J: good]]> 2017-10-25 15:08:57 UTC https://padlet.com/jmjackson/midterm2/wish/200451081 Team 12b https://padlet.com/jmjackson/midterm2/wish/200451177 What classifies a lens as thick?

A. A vergence change in the lens of 0.25D or greater.*

B. Power difference between front and back surface of 0.25D or greater.

C. A lens that is at least 5mm thick.

Dr. J: good]]> 2017-10-25 15:09:07 UTC https://padlet.com/jmjackson/midterm2/wish/200451177 Team 10b https://padlet.com/jmjackson/midterm2/wish/200451216 2017-10-25 15:09:11 UTC https://padlet.com/jmjackson/midterm2/wish/200451216 Team18b https://padlet.com/jmjackson/midterm2/wish/200451337 You have two prisms that are 15 prism diopter in the Risey. One is base 60 degrees and one is base 120 degrees. How much prism is the patient looking through.

A. 26 prism diopter BD
* B. 26 prism diopter BU
C. 15 prism diopter BU
D. 15 prism diopter BD

dr. J: *Risley ]]> 2017-10-25 15:09:22 UTC https://padlet.com/jmjackson/midterm2/wish/200451337 Team 2B https://padlet.com/jmjackson/midterm2/wish/200451430 Patient needs 5BO and 2BU over the left eye. What is the resultant prism power? 
A. 4.5
B. 6.3
C. 7.2
D. 5.4****

dr. J: also make sure you can figure out the angle]]> 2017-10-25 15:09:31 UTC https://padlet.com/jmjackson/midterm2/wish/200451430 team 16A https://padlet.com/jmjackson/midterm2/wish/200451849 If there is four prism diopter base up over the left eye and six prism diopters base down over left eye, then what is total prism diopter power and direction?
A. 2 BD*
B. 10 BD
C. 2 BU
D. 10 BU

Dr J: good]]> 2017-10-25 15:10:11 UTC https://padlet.com/jmjackson/midterm2/wish/200451849 Team 8A https://padlet.com/jmjackson/midterm2/wish/200452235 What is the net prism power and direction with 5 base up and 4 base out over OD? 

a) 6.4 @ 51.3 degrees
*b) 6.4 @ 128.7 degrees
c) 9 @ 51.3 degrees
d) 9 @ 128.7 degrees]]> 2017-10-25 15:10:48 UTC https://padlet.com/jmjackson/midterm2/wish/200452235 Team 21b: https://padlet.com/jmjackson/midterm2/wish/200452240 What is the net prism for a person that wears 8 BI over each eye?
A) 16 BO
B) 8 BO
C) 8 BI
*D) 16 BI

Dr. J comment: good]]> 2017-10-25 15:10:48 UTC https://padlet.com/jmjackson/midterm2/wish/200452240 Team 10b https://padlet.com/jmjackson/midterm2/wish/200452438 A small pinhole allows __ rays through but not __ rays.
A.  diverging; converging
B. converging; diverging
C. paraxial; peripheral *
D. peripheral; paraxial

Dr. J comment: good]]> 2017-10-25 15:11:08 UTC https://padlet.com/jmjackson/midterm2/wish/200452438 Team 7b https://padlet.com/jmjackson/midterm2/wish/200453318 The radius of curvature of the front surface of a lens is +5 cm.  The index of the lens is 1.6.  What is the front surface power of this lens? Assume the lens is in air.
A. -12 D
B. -8.3 D
C. +12 D**
D. +8.3 D

Dr. J comment: looks good]]> 2017-10-25 15:12:26 UTC https://padlet.com/jmjackson/midterm2/wish/200453318 Team 15a https://padlet.com/jmjackson/midterm2/wish/200453642 A patient wearing plus lenses looks to the left, what kind of prism is the patient's right eye looking through?

a. base up
b. base down
c. base in
d. base out ***
e. the prism takes a nap

Dr. J comment: good]]> 2017-10-25 15:12:58 UTC https://padlet.com/jmjackson/midterm2/wish/200453642 Team 9a https://padlet.com/jmjackson/midterm2/wish/200453760 If light enters a convex surface from a dense to rare medium, will the power be (+), (-) or 0?
A. (+)
*B. (-)
C. 0

Dr. J comment: looks good]]> 2017-10-25 15:13:13 UTC https://padlet.com/jmjackson/midterm2/wish/200453760