# Ophthalmic Optics Mt 2

113 Questions  I  By Tseemore

Changes are done, please start the quiz.

 1 Reflection is when light rays are redirected in a different direction, usually with a loss in amplitude
 A. True
 B. False
 2 What is refraction based on?
 A. Wavelength of light
 B. Index of the material
 C. Frequency of light
 3 As n _____, the speed of light _______.
 A. Decreases, decreases
 B. Increases, increases
 C. Increases, decreases
 4 The slower the light passes through a lens, the ____ it gets refracted.
 A. Less
 B. More
 C. No change
 5 A prism will bend light rays towards its ________.
 6 A prism will shift an image towards its ______.
 7 The prism diopter is the unite for prisms and it represents:
 A. The angle of deviation in degrees
 B. The angle of the apical angle
 C. The amount of image displacement
 8 An angle of 1 radian results in an arc with an equal length to the _______.
 A. 360deg/2pi
 B. 57deg
 C. 360 deg
 D. 2 of the above
 10 1 prism diopter = ______ radians
 11 1 prism diopter = _____ degrees
 A. 0.57
 B. 1.57
 C. 57
 12 Describe in words what a prism diopter is.
 13 How much power does a prism have if it is able to displace an image by 5cm at a viewing distance of 0.5m?
 A. 10 cm
 B. 100 cm
 C. 5cm
 D. 20 cem
 14 A 20 pd BU prism will displace an image by what distance at a viewing distance of 5m?  In what direction will the imave be displaced?
 A. 100 cm, towards base
 B. 100 cm, towards apex
 C. 50 cm, towards base
 D. 50 cm, towards apex
 15 A prism is able to displace an image by 4 degrees.  What is the power of the prism?
 16 What is the name of an instrument that is a tower of mini-prisms that are 1mm thick.
 A. Risley Prism
 B. Tower Prism
 C. Fresnel Prism
 17 Indicate the advantages of a Fresnel Prism.
 A. Can be attached to any current spectacle lenses
 B. Cheap
 C. Heavy weight and durable
 D. Easily changeable as the pt's condition changes
 18 Indicate the disadvantages of Fresnel Prisms
 A. Poor optics because of multiple prisms
 B. Heavy and at times irritating
 C. Expensive
 19 Indicate the clinical uses of prisms.
 A. Reduce eye turns
 B. Enhance biocularity/stereopsis
 C. Redirect image to pt's fovea to get similar retinal images
 20 One should orient the prism apex away from the deviating eye to place the image where the deviating eye is looking
 A. True
 B. False
 21 Your patient's right eye is misaligned with his left eye so that the right is higher than left.  What is the direction of the prism base that you would prescibe for the right eye?
 A. BU
 B. BD
 C. BI
 D. BO
 22 What components are used to specify a prism?
 A. Base direction
 B. Power
 C. Apex direction
 23 The coordinate system for prism is the same as with cylinder axis.
 A. True
 B. False
 24 Because the eye muscles are yoked, prism placed before one eye affects both eyes
 A. True
 B. False
 25 The full prism power must be placed on the eye that is deviated
 A. True
 B. False
 26 If a patient requires 4 BO total.  Indicate what possible prisms they can use.
 A. 2 BO OD, 2 BO OS
 B. 2 BO OD, 2 BI OS
 C. 1 BO OD, 3 BO OS
 27 Splitting prisms unequally can help to equalize lens thicknesses when lens powers between the 2 eyes are not equal
 A. True
 B. False
 28 With horizontal prisms, similar bases are _______.  With vertical prisms, similar bases are ________.
 29 A patient is prescribed horizontal prisms.  She is wearing 2 pd BO OD and 2 pd BO OS.  what is the total prismatic effect?
 30 A patient is prescribed horizontal prisms.  She is wearing 2 pd BI OD and 3 pd BO OS.  what is the total prismatic effect?
 31 A patient is prescribed vertical prisms.  He is wearing 3 pd BU OD and 3 pd BU OS.  What is the total prismatic effect?
 32 A patient is presribed vertical prisms.  He is wearing 2 pd BU OD and 2 pd BD OS.  What is the total prismatic effect? (2 answers possible)
 33 How does one deterine the 'reference eye'?
 A. Eye with most power in 180 meridian
 B. Eye with most power in 90 meridian
 C. Eye with most spherical equivalent power
 34 How can we ensure that there is no unwanted, induced prismatic effects?
 A. Optical center coincides with line of sight
 B. Optical center coincides with fovea
 C. Optical center coincides with geometric center
 35 For a positive lens, it is essentialy like 2 prisms with their bases facing ____.
 A. Outward
 B. Inward
 36 For a negative lens, it is essentially like 2 prisms with their bases facing ____.
 A. Outward
 B. Inward
 37 Prentice's Rule depends solves for:
 A. The power of the lens
 B. The amount of prism induced
 C. The distance away from the OC of the lens in cm
 38 The amount of prism induced requires knowledge of what factor(s)?
 A. Power of the lens
 B. Distance away from the OC of the lens
 C. The refractive error of the patient
 39 How much prism is induced if a +6.50 lens before the right eye is decentered 3mm nasally?
 A. 0.95 BI
 B. 1.95 BI
 C. 0.95 BO
 D. 1.95 BO
 40 A +4.00D lens is ordered for the right eye.  The Rx calls for 2 BI prism before the right eye.  How should the lens be decentered?
 A. Nasally
 B. Temporally
 C. 2 pd
 D. 4 pd
 41 A +3.50D lens is decentered 4 mm in and 5 mm down.  What is the resultant prismatic effect?
 A. 1.4 horizontally, 1.75 vertically
 B. 1.75 horizontally, 1.4 vertically
 42 If there is no prism prescribed for a patient, the PRP will be at the same location as the OC of the lens
 A. True
 B. False
 43 The distance between the optical center and the line of sight is the amount of:
 A. Induced prism
 B. Decentration
 C. MRP
 44 The major reference point (MRP) of the lens is where the prism amount is unequal to the amount that has been prescribed for the patient.
 A. True
 B. False
 45 What is the opticla difference between grinding in prisms and prism by decentration?
 A. Grinding provides less aberrations
 B. Grinding prodvides inferior optical quality
 C. There is no optical difference
 46 Your optician finds that the PD and the DBOC is off by 10 mm.  How much prism is induced and is it ok to dispense them?
 47 Your patient complains of fatigue from wearing his new glasses.  The DBOC is 64mm vs 60 mm as ordered.  What is the induced prismatic effect from each eye if the Rx is -2.00-100x180 OU?
 48 Your patient complains of vertical diplopia.  Marking the glasses OCs the OD OC is 4 mm higher than the OS OC.  The OS OC is centered over the pt's OS pupil.  How much prism is induced and in what direction if the Rxis +4.50-200x180 OU?
 49 Your patient needs 2 BO OD and 1.5 BO OS.  You would rather manipulate the OCs to create the prism.  How much decentration is necessary and in what direction to end up with the correct prism if the Rx in both eyes is -5.00 DS?
 50 What is the different between compounding and cancellation?
 A. Compounding involves subtraction and cancellation involves addition
 B. Compounding involves addition and cancellation involves subtracion
 C. For horizontal prisms, compounding occurs with opposite bases
 D. For vertical prisms, cancellation occurs with similar bases
 51 Your patient is complaning of vertical diplopia through her new glasses.  The right OC is 3mm ABOVE her pupil while her left OC is 4mm BELOW her left pupil.  Her Rx is -150-050X180 OU.  What is the prismatic effect of the OD, OS and OU?
 52 If a positive lens is shifted temporally what prismatic effect will that produce?
 A. BI
 B. BO
 C. BU
 53 If a negative lens is shifted inward what prismatic effect will that induce?
 A. BI
 B. BO
 C. BU
 54 If a +3.50 lens is deceneterd 4 mm in and 5mm down in front of the OD, what is the resultatnt prism?  Express as vertical and horizontal componentw.
 55 What factors affect the induced prism due to decentration?
 A. Cyl power
 B. Axis orientation
 C. Sphere power
 56 When is it apprpropriate to use Prentice's Rule?
 A. If decentration is perpendicular to the cyl axis
 B. If dencentration is parallel to the cyl axis
 C. If the decentration is oblique to the cyl axis
 57 What is the primsmatic effect of a plo-2.00x180 lens when it is decentered 5mm nasally over the right eye?
 58 What is the primsmatic effect of a plo-2.00x090 lens when it is decentered upward over the right eye?
 59 When do we use the Sine-Squared Method?
 A. If we decenter the sphero-cyl lens too much
 B. If the decentration is minimal
 C. If the Rx has an oblique axis
 60 What is the equation to find the power in a oblique meridian?
 61 What is the cyl power of the Rx -2.00-100X030 at the 180 meridian?
 62 What is the cyl power in the horizontal meridian (180) of plo+200x030? F= 0 + (sin2(30)) = +0.50
 63 What is the cyl power in the vertical meridian (90) of -2.50-200x060?
 64 How much prism is induced if the Rx is -4.00-1.50x045 if decentered nasally by 5mm over the OD?
 65 What factors are important for measuring the prism power at the center?
 A. Thickness difference btw apex and base
 B. Index of refraction
 C. Diameter of the prism or the distance btw apex and base
 66 How much prism is present in the middle of a lens that has an index of 1.50, diameter of 50mm?  The apex is 2mm and the base is 5mm.
 67 A -6.50 DS polycar lens is fitted into an oval frame with a horizontal diameter of 48mm.  The nasal edge thickenss is 4.2 mm and the temporal edge thickness is 5.8mm.  What horizontal prismatic effect is found exactly in the center of the lens?
 68 How much prism is induced if a lens with an Rx of -200-200x060 is decentered 3mm temporal over the OD?
 69 The DBOC of your new glasses measures 68mm but your PD is 64 mm.  How mch prism is induced in each eye and in what direction if your Rx is OD +200-400x060 OS +100-400x045.  Assume the PD is equally off OD and OS.   F180 = (+200) + (-400)(sin2(60)) = -100 --> (-100)(0.2) = 0.2 BI F90 = (+100) + (-400)(sin2(45)) = -100 --> (-100)(0.2) = 0.2 BI (0.2)+(0.2) = 0.4 BI (remeber that same bases will add in this case)
 70 Because the add power will always be positive, the power that you measure through the near add will always measure:
 A. More minus for a nearsighted patient
 B. More plus for a farsighted patient
 71 When neutralizing a pair of glasses you measure +200-075x180. The near add power is +200, the sphere and cyl target lines would read ____ and ____ when viewed through the segment.
 A. +4.00, -3.25
 B. +400, +3.25
 C. -400, +3.25
 72 Indicate the incorrect match.
 A. Age 40 --> 1D adds
 B. Age 50--> 1.5 D adds
 C. Age 60 --> 3 D adds
 73 Why do low myopic patients have the hardest time understanding presbyopia?
 74 You are neutralizing a pair of bifocal glasses and you get -200-100x135 in the distance portion.  If the power measured through the add is +0.50-100x135, what is the near add power?
 75 What type of bifocals have no ledge?
 A. Fused
 B. One piece
 C. Executives
 76 There are many different materials available for fused glasses designs.
 A. True
 B. False
 77 For a fused multifocal design, which area has the higher n?
 A. Distance
 B. Near
 C. All the same
 78 What type of materials are commonly used for One Piece MFs?
 A. Glass
 B. Plastic
 C. Hi index
 79 Cement Seg MFs are cement segments that are glued onto the distance portion of lenses
 A. True
 B. False
 80 Segment Widtch is measured from:
 A. Corner of seg to opposite corner
 B. Across the widest portion of the segment
 C. From the top of the segment to the bottom of the frame
 81 Segment Height is measured from:
 A. Top of the lens to the bottom of the segment
 B. Top of the segment to the bottom of the lens
 C. Bottom of frame to the top of the segment
 82 The Segment Depth is the:
 A. Widest portion of the lens
 B. The longest vertical dimension of the segment
 C. The longest horizontal dimension of the segment
 83 The Seg Inset is the distance between the distance OC and the near OC
 A. True
 B. False
 84 Describe how to measure a patient's seg height.
 85 Round segments only come in fused form
 A. True
 B. False
 86 Describe the pros and cons for round segments
 87 Which widths are available in round segments?
 A. 22
 B. 25
 C. 28
 D. 35
 E. 45
 88 In which occupations are round segments useful?
 A. Golfers
 B. Plumbers
 C. Electricians
 D. Painter/artist
 E. All of the above
 89 What is the most preferred bifocal design due to less distortion?
 A. Round segment
 B. Ultex
 C. Flat top
 90 What seg widths do flat top/D segs come in?
 A. 22
 B. 25
 C. 28
 D. 35
 E. 45
 91 As the ledge sticks out more for a flat top, the seg narrows
 A. True
 B. False
 92 Curved top are usually ______ and executives are usually ______.
 A. One piece; fused
 B. Fused; one piece
 C. Fused; fused
 93 Describe the difference between curved top and Panoptik segments
 94 How many optical centers do Executive bifocals have?
 A. 0
 B. 1
 C. 2
 95 Select the material and available seg widths for Ultex series.
 A. Plastic
 B. Glass
 C. 22,32,38,40
 D. 22,25,28,35
 96 What is the height of the intermediate portion for a trifocal lens usually?
 A. 6mm
 B. 7mm
 C. 8mm
 97 What was the Datum System used for?
 B. Determine placement of OCs and MF heights
 C. Determine cosmetically best seg choices
 98 How did the Box System update the Datum System?
 A. Added horizontal lines to create a box around the lens
 B. Added vertical lines to create a box around the lens
 C. Added oblique lines to measure OC
 99 In the Box System, the longest horizontal length is considered the _____ when referring to the frame and the _____ when referring to the lens
 A. Lens size; eye size
 B. Eye size; lens size
 C. Both are called eye size
 100 Another term for the lens size is:
 A. A measurement
 B. B measurement
 C. C measurement
 101 The longest vertical height of the frame is called the:
 A. A measurement
 B. B measurement
 C. C measurement
 102 Describe how to measure the C.
 103 C will always be greater than A
 A. True
 B. False
 104 What do we have to add to our A and B measurements to get the final measure?
 105 The geometric center is another name for the optical center.
 A. True
 B. False
 106 The effective diameter is the distance from the geometric center to the furthest pont on the frame.
 A. True
 B. False
 107 What does DBL stand for?
 A. ED x 2
 B. Bridge size
 C. Temple size
 108 How does one calculate the Frame PD (FPD)?
 A. A + DBL
 B. A + B
 C. B + DBL
 109 What 3 measurements are used in the Box System?
 A. Eye size
 B. Bridge width
 C. Temple length
 D. Effective diameter
 110 The larger the lens blank, the thinner the lens will be
 A. True
 B. False
 111 The goal is to use the smallest lens blank possible that will still fit in the frame
 A. True
 B. False
 112 The Minimum Blank Size (MBS) equals:
 A. ED+2mm
 B. Decentration + 2mm
 C. ED + total decentration + 2mm
 113 What would the MBS be for a single visin lens that is to be mounted in a frame having the following dimensions: A= 52mm DBL = 18 mm ED = 57 mm PD= 62mm
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