CPO

• Which is the best example of documentation of an eyeglass prescription on a lab order form?

  
  

  a) -1.00 -1.25 x10

  
  

  b) -1.00 -1.25 x010

  
  

  c) -1 -1.25 x10

  
  

  d) All of the Above

  b) -1.00 -1.25 x010
• On orders that include prism, both the amount of prism and the prism __________ direction should be specified.

  
  

  a) Base

  
  

  b) Apex

  
  

  c) Side

  
  

  d) Axis

  a) Base
• What instrument is used to measure the power of spectacle lenses?

  
  

  a) Tonometer

  
  

  b) Keratometer

  
  

  c) Lensometer

  
  

  d) Radiuscope

  c) Lensometer
• Which part of the lens measuring device indicates that the instrument has power?

  
  

  a) On/off switch

  
  

  b) Power wheel

  
  

  c) Lens stop

  
  

  d) Pilot light

  d) Pilot light
• What is the first procedure in lensometry?

  
  

  a) Turn the power wheel into plus

  
  

  b) Position spectacle on the lens stop

  
  

  c) Check the power calibration

  
  

  d) Focus the eyepiece


  d) Focus the eyepiece
• When measuring a lens, if both sets of lines making up the target sharply focus at the same time, the lens is a _______________ power lens.

  
  

  a) Spherical

  
  

  b) Spherocylindrical

  
  

  c) Plano spherical

  
  

  d) Plano cylindrical

  a) Spherical
• How is the power wheel scale graduated for power between -3.00 and +3.00?

  
  

  a) 1/8 D steps

  
  

  b) 1/4 D steps

  
  

  c) 3/8 D steps

  
  

  d) 1/2 D steps

  a) 1/8 D steps
• When measuring a lens, you find that the target sphere lines focus at -2.25 D with the cylinder axis wheel at 93 degrees, and the cylinder lines focus at -4.75 D without changing the cylinder axis. What would be the presentation of the lens?

  
  

  a) -2.25 -4.75 x093

  
  

  b) -2.25 -2.50 x093

  
  

  c) -2.25 -4.75 x003

  
  

  d) -2.25 -2.50 x003


  b) -2.25 -2.50 x093
• The amount of prism in a lens is measured using the lensometer _______________.

  
  

  a) Axis wheel

  
  

  b) Lens table

  
  

  c) Reticle

  
  

  d) Power wheel

  c) Reticle
• In the boxing system, the ________________ dimension is the largest vertical dimension measured between the two horizontal tangents to the bevel tips.

  
  

  a) A

  
  

  b) B

  
  

  c) MRP

  
  

  d) DBL

  b) B
• A __________ is used to measure the surface powers base curve of a lens.

  
  

  a) Thickness caliper

  
  

  b) PD ruler

  
  

  c) Lens clock

  
  

  d) Radiuscope

  c) Lens clock
• A colmascope is used to verify that a glass lens has been _______________.

  
  

  a) Scratch-resistance coated

  
  

  b) Heat-tempered

  
  

  c) Made with ultraviolet

  
  

  d) Made photochromatic

  b) Heat-tempered
• When verifying lens optical quality, the primary defect to search for is a localized area of _______________.

  
  

  a) Prism

  
  

  b) Low power

  
  

  c) Poor optics

  
  

  d) High power

  c) Poor optics
• Which of the following cylinder powers would be acceptable, according to American National Standards Institute (ANSI) standards, for a lens with a prescription of +3.00 -1.75 x100?

  
  

  a) -2

  
  

  b) -1.89

  
  

  c) -1.87

  
  

  d) -1.5

  c) -1.87
• What is the cylinder axis tolerance for a lens with a cylinder power of -1.00 D?

  
  

  a) ±2 degrees

  
  

  b) ±3 degrees

  
  

  c) ±5 degrees

  
  

  d) ±7 degrees

  ±3 degrees
• There can be no more than _______________ prism diopters of unwanted horizontal prism in a lens.

  
  

  a) 1/4

  
  

  b) 1/3

  
  

  c) 1/2

  
  

  d) 2/3


  d) 2/3
• There can be no more than _______________ prism diopter of unwanted vertical prism in a lens.

  
  

  a) 1/4

  
  

  b) 1/3

  
  

  c) 1/2

  
  

  d) 2/3

  b) 1/3
• The vertical segment location tolerance for a mounted lens is within ______ mm of specification.

  
  

  a) 1

  
  

  b) 1.5

  
  

  c) 2

  
  

  d) 2.5

  a) 1
• For special purpose prescription lenses, the thickness tolerance is ______ mm.

  
  

  a) ±0.3

  
  

  b) ±0.4

  
  

  c) ±0.5

  
  

  d) ±0.6

  a) ±0.3
• If a base curve is specified when a lens is ordered, it should be supplied within ______ D.

  
  

  a) ±0.37

  
  

  b) ±0.50

  
  

  c) ±0.62

  
  

  d) ±0.75

  d) ±0.75
• If the distance PD is 64 and the near is 60, what is the seg insert?

  
  

  a) 1mm

  
  

  b) 2mm

  
  

  c) 3mm

  
  

  d) 4mm

  d) 4mm
• What is the description of a gradient tint?

  A gradient tint on a lens lightens towards the bottom of the lens.
• When focusing the eyepiece of a lensometer, why is it important to stop turning the eyepiece when a sharp focus is first obtained?

  Turning the eyepiece past the point of focus could cause accommodation.
• When the lensometer was calibrated, the target focused sharply at +0.25 and was blurred at zero. You are neutralizing a lens and have a reading of +1.00 on the lensometer. How would you record this reading?

  
  

  a) +0.75

  
  

  b) +1.00

  
  

  c) +1.25

  
  

  d) You should not use a lensometer that is not properly calibrated.

  a) +0.75
• If both sets of lines making up the target sharply focus at the same time, the lens being neutralized is a:

  
  

  a) Prism

  
  

  b) Spherocylinder

  
  

  c) Sphere

  
  

  d) Warped lens

  c) Sphere
• If the two sets of lines in the projected target will not come into focus at the same time, the lens being neutralized is a:

  
  

  a) Prism

  
  

  b) Spherocylinder

  
  

  c) Sphere

  
  

  d) Warped lens

  b) Spherocylinder
• The cylinder lines will focus at a more ________________ power reading than the sphere lines when neutralizing a lens in minus cylinder.

  
  

  a) minus

  
  

  b) plus

  
  

  c) clear

  
  

  d) strong

  a) minus
• If the sphere lines focused and unbroken at -1.00, axis 100, and the cylinder lines focus at -1.50, how would the prescription be recorded?

  
  

  a) -1.00 -1.50 *100

  
  

  b) -1.50 -1.00 *100

  
  

  c) -1.00 -0.50 *100

  
  

  d) -1.00 -0.50 *010

  c) -1.00 -0.50 *100
• If the sphere lines are focused and unbroken at +3.00, axis 090, and the cylinder lines focus at +1.00, how would the prescription be recorded?

  
  

  a) +3.00 +1.00 *090

  
  

  b) +3.00 -1.00 *090

  
  

  c) +1.00 -3.00 *090

  
  

  d) +3.00 -2.00 *090

  d) +3.00 -2.00 *090
• When measuring a lens in minus cylinder, if the cylinder lines focus at a more plus reading than the sphere lines, you should rotate the axis wheel by __________ degrees.

  90
• If the vertical target lines in the distance prescription focus at -2.00 and the same lines focus at +0.50 in the near segment of the lens, the near power should be recorded as

  
  

  a) +0.50

  
  

  b) +2.50

  
  

  c) +2.00

  
  

  d) -2.50

  b) +2.50
• An important factor in measuring lenses with an automated lensometer is keeping the lens __________ against the lens stop.

  Flat
• Which of the following must be accounted for when measuring prism?

  
  

  a) The patient's PD

  
  

  b) The orientation of the prism

  
  

  c) The location of the lateral PRP, or MRP

  
  

  d) All of the above

  d) All of the above
• Which glasses measurement is the same as the DBL?

  
  

  a) Frame eye size, or "A" dimension

  
  

  b) "B" dimension

  
  

  c) Distance between lenses, or "DBL"

  
  

  d) Bridge size

  d) Bridge size
• Which glasses measurement is the largest horizontal measurement?

  
  

  a) Frame eye size, or "A" dimension

  
  

  b) "B" dimension

  
  

  c) Distance between lenses, or "DBL"

  
  

  d) Bridge size


  a) Frame eye size, or "A" dimension
• What is the separation of the two lenses in a frame at the nasal bevel tips referred to as?

  
  

  a) Frame eye size, or "A" dimension

  
  

  b) "B" dimension

  
  

  c) Distance between lenses, or "DBL"

  
  

  d) Bridge size

  c) Distance between lenses, or "DBL"
• Which glasses measurement is the largest vertical measurement?

  
  

  a) Frame eye size, or "A" dimension

  
  

  b) "B" dimension

  
  

  c) Distance between lenses, or "DBL"

  
  

  d) Bridge size

  b) "B" dimension
• Which of the following lenses has the least amount of power in the vertical meridian?

  
  

  a) +2.00 -0.50 x180

  
  

  b) +1.50 -1.00 x180

  b) +1.50 -1.00 x180
• Which of the following lenses should be measured first when verifying vertical lens positioning, or measuring the amount of vertical prism in the spectacles?

  
  

  a) +2.00 -0.50 x180

  
  

  b) +1.50 -1.00 x180

  a) +2.00 -0.50 x180
• When tapping a glass lens with your fingernail. the sound will be _______________ than the _______________ sound of a plastic lens.

  sharper, dull