NCLE - Optical Nerd · 2020. 7. 24. · 4. NCLE Preparation Exam. 16. Ocular signs, of aging...

NCLEPRACTICE TEST #2

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NCLE Preparation Exam

PREFIT, PREPARATION AND EVALUATION

1. Which of the following medications may affect successful contact lens wearA. AntacidsB. AntihistaminesC. AspirinD. Laxatives

2. Which term refers to a sensitivity to light?A. PresbyopiaB. PhotophobiaC. PannusD. Ptosis

3. The following is an example of what type of astigmatism:K's 42.50 @ 180 / 40.50 @ 90

A. With-the-rule astigmatismB. Lenticular astigmatismC. Against-the-rule astigmatismD. Irregular astigmatism

4. The cornea receives nutrients from: 1) Aqueous humor2) Tears3) Limbal blood vessels4) Orbicularis occuli

A. 1, 3 & 4B. 2 & 3C. 1,2 & 3D. 3 & 4

5. The increased loss of ability of the crystalline lens to accommodate is called:A. PresbyopiaB. MyopiaC. HyperopiaD. Aphakia

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6. Which instrument can provide simultaneous information about the cornea, lids, conjunctiva, lashes, contact lens surface and fit?A. RadiuscopeB. CorneoscopeC. Slit lampD. Keratometer

7. The pre-corneal tear film is composed of three layers. They are:A. Lysozyme, oil, lacrimalB. Sebaceous, mucoid, BAKC. Lipid, aqueous, mucinD. Water, mucoid, lysozyme

8. Transpose the following Rx into minus cylinder form:Rx -4.50 +1.25 x 94

A. -3.25 -1.25 x 4B. -3.25 -1.25 x 94C. -4.50 -1.25 x 4D. -5.75 -1.25 x 4

9. The average pH value of the human tear is: A. 6.6B. 7.4C. 7.8D. 10.0

10. If the manufacturer's guidelines suggest a minimum of 4 hours for disinfection, what would you suggest to the patient?

A. Never leave lenses in disinfectant Overnight

B. 2 to 3 hours is probably enoughC. Use surfactant cleaner and preserved salineD. A minimum of 4 hours is required

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11. The main supply of oxygen to the corneal epithelium is derived from the:A. StromaB. Collagen fibrilsC. Basal membraneD. Tear film

12. What is the term for the condition in which there is loss of vision without any apparent disease to the eye?A. AmblyopiaB. AniridiaC. AstigmatismD. Aphakia

13. Which auxiliary trial lens will extend the keratometer to approximately 30.00 D? A. +1.00 DB. +1.25 DC. -1.00 DD. -1.50 D

14. Which step should be performed first when taking keratometer measurements?A. Rotate the drum to reflect the

cylinder axisB. Adjust the patient so that they are

comfortableC. Focus the eyepieceD. Cover the patient's eye that is not being measured

15. The following is an example of what type of astigmatism?K's 44.00 @ 180 / 44.50 @ 90Rx -3.00 -2.50 x 180

A. Lenticular astigmatismB. Against-the-rule astigmatismC. Irregular astigmatismD. Oblique astigmatism

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16. Ocular signs, of aging include: 1) Tear film abnormalities2) Reduced lid elasticity3) Lens opacities4) Loss of accommodation

A. 1 onlyB. 1&3C. 2&4D. All of the above

17. Transpose the following Rx into minus cylinder form: Rx +1.50 +1.00 x 75 A. +1.50 -1.00 x 75B. +2.50 -1.00 x 75C. +2.50 - 1.00 x 165D. +2.50 - 1.00 x 175

18. The pre-corneal tear film provides:1) A smooth optical surface2) Metabolic nutrients to the epithelium3) Oxygen to the endothelium4) Limbal hyperemia

A. 1&3B. 1&2C. 2&3D. 3&4

19. The cornea has five distinct layers. In order from anterior (front) to posterior (back) they are:

A. Epithelium, Descemet's membrane, Stroma, Bowman's membrane, EndotheliumB. Endothelium, Stroma, Bowman's membrane, Descemet's membrane, EpitheliumC. Epithelium, Bowman's membrane, Stroma, Descemet's membrane, EndotheliumD. Endothelium, Bowman's membrane, Stroma, Descemet's membrane, Epithelium

20. The normal cornea is transparent due to the pump action creating proper fluid balance. Which layer of the cornea is most responsible for maintaining this function?

A. EndotheliumB. Basal membraneC. EpitheliumD. Bowman's membrane

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21. A normal tear break up time is:A. 6 –7 secondsB. 10 – 12 secondsC. Less than 5 secondsD. None of the above

22. A whitish haze in the peripheral corneal stroma which does not stain and is often seen in the elderly is known as:

A. NeovascularizationB. DellenC. Arcus SenilusD. Fuch's Dystrophy

23. Patients with keratitis sicca are more prone to:A. Secondary infectionsB. Loss of eyelashesC. Losing their contact lensesD. Steepening corneas

24. Upon removal of the crystalline lens, the patient is:A. AphakicB. MyopicC. HyperopicD. Astigmatic

25. The following Rx represents: OD +2.00 = 20 / 20OS -3.00 -2.00 x 180 = 20 / 20A. PresbyopiaB. AnisometropiaC. AmblyopiaD. Emmetropia

26. The above patient will best achieve stereopsis with which of the following modalities?A. Contact lensesB. SpectaclesC. IOLD. Scleral lenses

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27. Tom's spectacles with a power of -12.00 +.50 x 90, sit 10 mm in front of his cornea. The likely soft contact lens prescription for Tom would be:

A. -10.50 DB. -11.75 DC. -12.00 DD. -12.50 D

28. The keratometer is an instrument used to measure:A. Corneal curvatureB. Lens powerC. Lens diameterD. Lens thickness

29. An instrument used to evaluate corneal irregularity by reflecting concentric circles from the patient's cornea is called a:

A. Burton LampB. Con-Ta-ChekC. TopogometerD. Placido Disk

30. Which auxiliary trial lens will extend the keratometer to approximately 61.00 D? A. -1.25 DB. +1.25 DC. -1.50 DD.+1.50 D

31. Wearing lenses in high attitudes and dry environments may result in complaints of all but the following:

A. PhotophobiaB. ChalazionC. GrittinessD. Burning sensation

32. Patients with which of the following occupations can successfully wear contact lenses?

A. Arc weldersB. FirefightersC. TeachersD. All of the above

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33. Transient keratometric mire distortion is usually due to:A. Pre-ocular tear filmB. Prolonged rigid lens wearC. Prolonged soft lens wearD. Irregular corneal astigmatism

34. In against-the-rule astigmatism, the steepest corneal meridian:A. Is at or near 180 degreesB. Is at or near 135 degreesC. Is at or near 90 degreesD. Is at or near 45 degrees

35. Irregular mires on a keratometer may be indicative of:A. Dry eyes or excessive mucoid secretionsB. KeratoconusC. Contact lens induced corneal warpageD. All of the above

36. In an alignment lid attachment RGP fit, the fluorescein pattern should show:A. Apical clearance and 360 degrees of bearing in the mid-peripheryB. A thin, even layer of fluorescein and less than 180 degrees of bearing in the

mid-peripheryC. Apical bearing and tear pooling inferiorlyD. Apical bearing and maximum edge lift

37. In an RGP wearer, an arcuate stain on the cornea may be due to:A. Failure to close the lids completely

when blinkingB. A lens fit that is excessively flatC. Poorly blended secondary curvesD. Solution sensitivity

38. In a Schirmer I test:A. The patient should produce sufficient tears to saturate the paper strip in 3 minutesB. An anesthetic drop is instilled in the eye to eliminate reflex tearingC. Fluorescein must be instilled in the eye to measure tear film break-up timeD. A patient with an unanesthetized eye and normal tear output should wet at least 15

mm of the filter paper in 5 minutes

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39. In a Schirmer II test:A. Break-up time must be at least 10 seconds if a patient is to be a successful contact

lens wearerB. An anesthetic drop is instilled before the Schirmer strip is inserted to eliminate the

reflex tearing caused by the filter paperC. A normal reading guarantees that the patient is producing sufficient tears for

successful contact lens wearD. If the patient wets the entire Schirmer strip, they have xerosis and should not wear

contact lenses

40. Rose bengal testing:A. Is usually not necessary because the same information can be obtained by

Schirmer testingB. Will stain devitalized conjunctival epithelial cells brightlyC. Will only stain healthy epithelial cellsD. Can be used to evaluate RGP lens fits instead of fluorescein

41. When evaluating tear film break-up-time:A. Rose bengal will give a more accurate reading than fluoresceinB. Fluorescein should be instilled in the eye and the patient not allowed to blink until a

reading is takenC. A break-up-time of less than 10 seconds may preclude success with contact lensesD.The patient is seated at the keratometer, fluorescein is instilled in the eye and the

patient told to blink to spread the fluorescein evenly across the cornea before timing is begun

42. The preservative in contact lens solutions:A. Must demonstrate efficacy in killing bacterial, viral and fungal microorganismsB. Is usually a mercury compound such as thimerosalC. Must kill all microorganisms on a contact lens in a 4 hour soak periodD. Is formulated to keep microorganisms from multiplying in a bottle of contact lens

solution after it has been opened

43. A patient wearing a high horizontal prismatic correction for a motility problem:A. Will be able to have the same amount of prism added to the contact lens to control

their strabismusB. May experience diplopia when fit with contact lensesC. VAR probably not need any prismatic correction with contact lenses since they sit

directly on the eyeD. May develop nystagmus with contact lenses unless the prism is added

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44. A pre-presbyopic myopic patient who is still able to read with single vision glasses may find that:

A. They are unable to see fine print when fit with contact lensesB. If the vertex distance is reduced, near vision will be clearerC. Monovision is impossible to adapt toD. It is even more difficult to see the computer than to read with contact lenses that

contain their distance prescription

45. Amy's +8.50 D spectacles sit 12 mm from the cornea. The power of a soft contact lens for Amy, properly vertexed, would be:

A. +8.00 DB. +8.50 DC. +9.50 DD. +11.00 D

46. Which of the following choices would work best for the patient's visual needs, given the following information:

K's 44.00 @ 180 / 45.25 @ 90Rx -3.00 +0.25 x 90A. RGP lens: 45.25 -3.00B. RGP lens with toric posterior curvesC. Soft toric lensD. Spherical soft lens

47. Which of the following set of lens specifications would best simulate an intrapalpebral RGP fitting given the following information:

K's 42.00 @ 180 / 43.00 @ 90Rx -2.00 -1.00 x 180Upper lid positions 2 mm above the superior limbus A. 42.50 -2-50 8.5B. 42.00 -2.00 9.5C. 41.50 -1.50 8.5D. 41.50 -1.50 9.5

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48. Which contact lens would best correct this patient's visual needs, given the following information:

K's 46.00 @ 180 / 45.50 @ 90Rx -3.00 -1.50 x 90

A. A soft spherical lensB. A soft toric lensC. A back surface toric RGP lensD. A front surface toric RGP lens

49. Which of the following material components has the highest gas permeability?A. FluorineB. PMMAC. ButyrateD. Silicone

50. When documenting in a patient's chart on a new-fitting recheck, which of the following are not necessary?

A. Visual acuity with the new lensesB. Notation of wearing time in lenses todayC. Any concerns from the patientD. Sister's lens type that has caused no problems

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DETERMINE LENS TYPE AND DESIGN CONTACT LENS PARAMETERS

51. Application of fluorescein should be used in which of the following situations?A. Evaluation of a rigid gas permeable lens fitB. Evaluation of soft contact lens parametersC. Evaluation of vascularization of the corneaD. Evaluation of rigid gas permeable lens over-refraction

52. If the diagnostic rigid gas permeable lens placed on the eye results in minimal movement, which of the following will increase the movement on the lens ordered for the patient?

A. Decreasing overall lens diameterB. Increasing overall diameterC. Increasing optic zone diameterD. Increasing sagittal depth

53. If a soft contact lens decenters laterally, exposing a portion of the patient's limbus, what change in parameter would improve this situation?

A. Decreasing lens diameterB. Increasing lens diameterC. Flattening the base curveD. Increasing the center thickness

54. When evaluating a diagnostic soft lens on a patient, you notice that movement is sluggish after only a few minutes. Which of the following changes would you make to the lenses that are ordered for the patient?

A. Increase overall lens diameterB. Steepen base curveC. Flatten base curveD. Add -0.50 D to the lens power

55. Which of the following lens designs would provide the best visual result for this patient?K's 43.00 @ 180 / 46.00 @ 90Rx -3.00 sphere

A. Soft toric lensB. Spherical rigid gas permeable with increased center thicknessC. Truncated rigid gas permeable lensD. Soft spherical lens

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56. Which edge design is recommended for a + 15.00 D aphakic RGP lens?A. HyperflangeB. Lenticular myoflangeC. Concentric designD. Intrapalpebral design

57. Which of the following lens designs would provide the best visual result for this patient?K's 42.00 @ 180 / 42.50 @ 90Rx -3.50 -1.75 x 180

A. Spherical rigid gas permeable lensB. Spherical soft lensC. Soft toric lensD. Back surface toric rigid gas permeable lens

58. What Rx would be ordered for a rigid gas permeable lens fit "on K"?K's 43.00 @ 180 / 44-00 @ 90Rx -3.00 +1.00 x 90

A. - 1.00 DB. - 2.00 DC. -3.00 DD. -4.00 D

59. To aid in the positioning of a rigid prism ballast lens riding too low and slipping underneath the lower lid, which of the following might be helpful?

A. HyperflangeB. More prismC. TruncationD. Thinner edge design

60. The following rigid gas permeable diagnostic lens is placed on a patient's eye:43.50 -2.00 9.2

An over-refraction is performed with the following results: plano +1.50 x 95 Which of the following lens parameters would you order for the patient?A. 43.50 -0.50 -1.50 x 5 9.2

B. 43.50 -2.00 -1.50 x 5 9.2C. 43.50 plano -1.50 x 95 9.2D. 43.50 plano + 1.50 x 5 9.2

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61. The following soft lens is placed on a patient's eye: 8.8 -4.00 14.0An over-refraction is performed resulting in -0.75 D sphere. Which of the following lens parameters would you order for the patient?

A. 8.8 -3.25 14.0B. 8.8 -4.00 14.0C. 8.8 -4.75 14.0D. 8.8 -5.25 14.0

62. In an RGP lens, a poorly finished transitional zone between the optic zone and the lens edge can be evaluated by:

A. RadiuscopeB. LensometerC. Profile analyzerD. Contacto gauge

63. During the diagnostic evaluation of the following patient, the lens rotates 10 degrees to the right. Which of the following lens parameters would you order for the patient?Patient's Refraction -2.50 -1.00 x 170Diagnostic lens 8.7 -2.50 -1.00 x 170A. 8.7 -2.50 - 1.00 x 160B. 8.7 -2.50 - 1.00 x 170C. 8.7 -2.50 - 1.00 x 180D. 8.7 -2.50 -1.00 x 10

64. Which of the following lens designs would not provide a good visual result for this patient?

K's 42.50 @ 180 / 44.00 @ 90Rx -2.50 +1.50 x 90

A. Soft toric lensB. Soft spherical lensC. Spherical rigid gas permeable lensD. Aspheric rigid gas permeable lens

65. An excellent material for a patient with keratoconus would be:A. PolymaconB. CrofilconAC. Bufilcon AD. Fluoro Silicone Acrylate

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66. A prism ballast RGP lens requires how much prism for proper orientation? A. 0.75 to 1.50 DB. +3.00 D at 6 o’clockC. 1.50 to 3.00 DD. Always 0.75 D

67. Which of the following could be considered in the fitting of a keratoconus patient?1) Aspheric2) McGuire3) Soper4) Tangent Streak

A. 1 &2B. 2&3C. 3&4D. 1, 2 & 3

68. The following soft lens is placed on a patient’s eye:An over-refraction is performed with the following results:

8.4 -2.00 14.2-1.00 –0.50 x 174

Which of the following lens parameters would you order for the patient? A. 8.4 -2.00 14.2B. 8.4 -2.75 14.2C. 8.4 -3.25 14.2D. 8.4 -3.75 14.2

69. Given the following information:K’s 45.00 @ 180 / 44.00 @ 90Rx –3.00 +1.00 x 180

Upper lid positioned at the superior limbus

Which of the following set of lens specifications would best simulate an intrapalpebral rigid lens fitting?A. 43.50 –1.50 8.5B. 43.50 –1.50 9.5C. 44.50 –2.00 8.5D. 44.50 –2.50 8.5

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70. Given the following information, which of the following set of lens specifications would best simulate a lid attachment rigid lens fitting?

K’s 42.00 @ 180 / 43.00 @ 90Rx –2.00 –0.87 x 180

Upper lid positioned 2 mm below the superior limbus

A. 41.50 –1.50 9.5B. 42.50 –2.50, 8.5C. 43.00 –2.50 9.5D. 43.00 –3.00 8.2

71. Which of the following bifocal designs represents a translating design?A. Diffraction designB. Crescent designC. Reverse centrad designD. Concentric design

72.Given the following information, which of the listed rigid lens designs would you order to best correct this wearer's vision?

K's 42.00 @ 180 / 45.00 @ 90Rx -3.00 -2.25 x 180

A. 42.00 / 45.00 -3.00 -2.25 (Rx form)B. 42.00 -3.00 -2.75 x 177 prism ballastedC. 42.00 -3.00D. 45.00 -3.00

73. The performance of a soft toric lens depends on:1) Corneal topography2) Lid shape3) Lid positioning4) Lid tightness

A. 1 onlyB. 1& 3C. 2&3D. All of the above

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74. Given the following information, which of the following RGP lens designs would you order to best correct this patient's vision?

K's 45.00 @ 180 / 42.00 @ 90Rx -2.00 -4.25 x 90

A. 45.00 -2.00B. 42.00 -2.00 -4.25 x 90 prism ballastedC. 42.00 -2.00D. 42.00 / 45.00 -2.00 / -5.75 (drum readings)

75. Given the following information, which of the following RGP lens designs will best correct this wearer's vision?

K's 42.50 @ 180 / 42.50 @ 90Rx -3.00 - 1.00 x 90

A. Bitoric designB. Anterior toric designC. Spherical designD. Soper Cone design

76. Given the following refraction and K readings, select the correct base curve and power recordings (drum readings):

K's 44.00 @ 180 / 4 1.00 @ 90Rx - 1.00 -3.00 x 90

A. 41.00 / 44.00 -1.00 / -3.00B. 41.00 / 44.00 -1.00 / -4.00C. 41.00 / 44.00 -4.00 / - 1.00D. 44.00 / 41.00 -1.00 / -3.00

77. Which of the following is not necessary to consider when fitting RGP aphakic contact lenses?A. Vertex distanceB. Minus-carrier lenticular designsC. Proper lens centrationD. Hyperflange designs

78. A bifocal lens in which the power gradually changes from the central area of the lens to the periphery is known as:A. An aspheric lensB. A juxtapositioned lensC. A monocentric lensD. A crescent lens

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79. An aphakic patient with K readings of 40.50 @ 180 / 41.25 @ 90, large palpebral fissures and flaccid lower lids is a good candidate for:A. A single cutB. A myoflange lenticularC. A hyperflange lenticularD. A back toric

80. The patient has a horizontal visible iris diameter (HVID) of 12.5 mm. 'Me best choice for initial soft lens diameter would be:A. 13.0 mmB. 13.5 mmC. 14.5 mmD. 15.5 mm

81. A single cut aphakic lens is best suited for patients with apertures andcorneas:

A. Small / flatB. Small / steepC. Large / flatD. Large / steep

82. Where is the power curve on a spin-cast soft lens?A. The front surfaceB. The back surfaceC. Within the lensD. Around the edge

83. Keratoconus and penetrating keratoplasty fittings are best accomplished by which of the following methods?

A. NomogramB. K's and RxC. Diagnostic fittingD. Molded impression

84. The following ametropia frequently results in high riding rigid lenses:A. High myopiaB. High hyperopiaC. AphakiaD. Presbyopia

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85. A good example of a bifocal contact lens that may rotate without vision impairment is:A. AsphericB. ExecutiveC. Fused crescentD. Translating

86. A toric soft lens will correct:A. Residual astigmatismB. Moderate astigmatism (greater than 2.00 D)C. Low astigmatism (0.75 to 2.00 D)D. All of the above

87. A lens fitted for keratoconus should:A. Flatten the apexB. Ride highC. Align the apexD. Ride low

88. Therapeutic soft lenses should be fit with minimal movement in which case?A. Keratitis siccaB. TrichiasisC. Recurrent erosionD. Keratoconus

89. The best option for patients with Giant Papillary Conjunctivitis (GPC), or those who are cooks or hairdressers is:A. Tinted soft lensesB. Disposable lenses for daily wear onlyC. Traditional soft lenses that are replaced on an annual basisD. Extended wear lenses

90. Which of the following is a translating bifocal lens design?A. ConcentricB. AsphericC. DiffractiveD. Segmented

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91. Prism ballast, double slab-off and peri-ballast are all what type of lens design?A. Soft toricB. BifocalC. TherapeuticD. Spherical

92. In choosing the diameter of a soft lens, what is the general rule of thumb?A. 1.0 mm larger than HVIDB. 2.0 mm. larger than HVIDC. 3.0 mm larger than HVIDD. None of the above

93. K's 42.00 @ 170 / 43.00 @ 80Rx -3.00 -1.00 x 170

Given the above Rx and K's, the following diagnostic toric soft lens was used: 8.8 -3.00 -1.00 x180During the diagnostic evaluation, the above lens rotated 10 degrees clockwise. The lens ordered should have an axis of:A. 10 degreesB. 160 degreesC. 170 degreesD. 180 degrees

94. Which of the following statements is correct?A. High Dk RGP lenses have greater stability and deposit resistance than lower Dk

materialsB. Use of an enzymatic cleaner is mandatory with fluoro-silicone acrylate materialsC. Fluoro-silicone acrylate materials have "non-stick" qualities that enable patients to

blink protein and other deposits off the lens surfaceD. Silicone acrylate materials have a positively charged surface that repels lipid and

protein deposits

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95. Given the following information:K's 42.00 @ 180 / 42.00 @ 90Rx -3.00 -2.00 x 180

A. A back surface toric RGP lens will probably be necessary to achieve optimum visual acuity

B. A bitoric RGP lens will probably be necessary to achieve optimum visual acuityC. A soft spherical lens will provide the best fit and visual acuity because the patient

has a spherical corneaD. A front surface toric RGP lens will probably be necessary to correct the patient's

residual astigmatism

96. A patient's K readings are 43.50 @ 180 / 41.50 @ 90. A spherical RGP lens can be expected to:A. Displace down and in or down and out with each blinkB. Position under the upper lid to provide a superior lid attachment, alignment fitC. Lock on to the cornea nasally or temporallyD. Establish a fulcrum at 3 and 9 o'clock in the horizontal meridian

97. Which special RGP lens design would be beneficial for this patient given the following information?

K's 44.00 @ 180 / 46-50 @ 90Rx -11.00 +2.50 x 90

A. HyperflangeB. Back toric designC. Thick edge designD. Myoflange

98. During the diagnostic evaluation of the following patient, the lens rotates 10 degrees to the left. Which of the following lens parameters would you order for the patient? Patient's Refraction -3.00 -1.25 x 160Diagnostic lens 8.4 -3.00 -1.25 x 180 14.5A. 8.4 -3.00 -1.25 x 160 14.5B. 8.4 -3.00 -1.25 x 170 14.5C. 8.4 -3.00 -1.25 x 180 14.5D. 8.4 -3.00 -1.25 x 10 14.5

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99. A patient is diagnostically fit with a rigid gas permeable lens with the following parameters: 42.50 -3.00 9.5. If you wish to flatten the lens to cornea relationship, which of the following lenses would you order?A. 42.00 -2.50 10.0B. 42.50 -3.00 9.0C. 43.00 -3.50 9.5D. 43.50 -3.50 9.0

100. Contact lens are most often specified in:A. Back vertex powerB. Sphero-cylinder powerC. Power in situD. Posterior apical radius

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INSTRUCTION AND DELIVERY PROCEDURE

101. The tolerance for the overall lens diameter according to the ANSI standards is: A. + 0.005 mmB. + 0.05 mmC. + / - 0.01 mmD. +/ -0.1 mm

102. All of the following will enable the practitioner to verify the overall rigid gas permeable lens diameter except:A. Slot gaugeB. ShadowgraphC. Measuring magnifierD. Radiuscope

103. Placing the concave side of a rigid gas permeable lens against the lens stop of the lensometer, will provide you with which of the following?A. Back vertex powerB. Front vertex powerC. Best vertex powerD. Closest vertex power

104. An instrument that allows simultaneous verification of lens diameter, optic zone width and peripheral curve width is:A. Measuring magnifierB. OphthalmometerC. Profile analyzerD. Radiuscope

105. Assessment of the quality of the peripheral curves (blends) of a rigid contact lens is achieved by the use of the:A. Profile analyzerB. ShadowgraphC. KeratometerD. Burton lamp

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106. The instrument used for magnification of the edge of a rigid contact lens is a:A. KeratometerB. ShadowgraphC. Profile analyzerD. V-groove gauge

107. The tolerance for lens power under + / -10.00 D is: A. 0. 12 DB. 0.25 DC. 0.37 DD. 0.50 D

108. A warped lens will showbase curve(s) on the radiuscope and a power on the lensometer.A. One / sphericalB. Two / sphero-cylindricalC. One / sphero-cylindricalD. Two / spherical

109. Which of the following will NOT measure contact lens parameters?A. KeratometerB. RadiuscopeC. Burton lampD. Thickness gauge

110. Prolonged periods of reading in contact lenses may lead to lens discomfort due to:A. Decreased blinkingB. Corneal temperature changesC. Accommodative responseD. Neovascularization

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111. Which of the following statements is most accurate:A. Routine cosmetic daily wear patients should be seen at 3 month intervals for a

contact lens evaluationB. Patients with a history of GPC should be refit with disposable soft lenses and

followed on a bi-weekly basis for 6 monthsC. New soft lens fits should be seen one week, one month, three months and 6

months from the time of their initial fit, then every 6 to 12 monthsD. Patients who are wearing RGP lenses after penetrating keratoplasty need fewer

follow-up visits than keratoconus patients because their corneas are now spherical

112. Which of the following materials would least likely require a weekly enzymatic cleaner?A. Polymethylmethacrylate.B. HydrophilicC. Hydroxyethyl MethacrylateD. Silicone acrylate

113. Which type of lens would best satisfy this patient's visual needs given the following information?

K's 43.00 @ 160 / 44.00 @ 75 3+ distortionRx -2.00 + 1.00 x 75

A. Spherical soft lensB. Soft toric lensC. Soft bifocal lensD. Spherical RGP lens

114. A rigid contact lens measures +15.00 BVP. The FVP will measure:A. A lesser dioptric readingB. A greater dioptric readingC. An identical dioptric readingD. An astigmatic reading

115. Which of the following preservatives has a low incidence of ocular sensitivity with soft contact lenses?A. Sorbic acidB. ChlorbutanolC. Benzalkonium ChlorideD. Thimerosal

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116. Patients who are fit with lenses that will be worn overnight on a flexible or extended wear basis:A. Should be seen as early as possible in the morning for follow-up of overnight

wearB. Should have their follow-up visits late in the day to evaluate their lenses and

identify problems related to overnight wearC. Should be scheduled for a follow-up visit 2 weeks after the initial fittingD. Will need minimal follow-up if they have worn daily wear lenses successfully

117. The base curve of a rigid lens was ordered 7.84 mm and was received measuring7.94 mm. This lens is than ordered.A. 0.50 D steeperB. 1.00 D steeperC. 0.50 D flatterD. 1.00 D flatter

118. One might utilize which of the following lens designs given the following information:K's 46.00 @ 75 / 48.50 @ 165 +2 distortionRx -7.00 -3.50 x 165irrregular retinoscopy reflexes

A. Soper keratoconus designB. Myoflange designC. Front surface toric RGP designD. Mandell design

119. Given the following information: K's 42.50 @ 180 / 44.50 @ 90 Rx -3.50 -2.50 x 90Select the lens power if the lens is ordered one half diopter steeper than K: A. -3.50 DB. -4.00 DC. -4.75 DD. -6.00 D

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120. The FDA has recommended that extended wear contact lenses be worn for a maximum of:A. 7 daysB. 14 daysC. 30 daysD. 45 days

121. Which of the following preservatives is a mercury based compound?A. Sorbic acidB. ThimerosalC. Benzalkonium chlorideD. Polyquad

122. Carole's contact lenses are fit on flat K. Her refraction is -5.00 +2.00 x 90. What is the power of her contact lenses?A. -3.00 DB. -4.00 DC. -5.00 DD. -7.00 D

123. When verifying a rigid lens on a radiuscope, you notice that the mires are not in focus in all principle meridians. This might indicate a:

1) Warped lens2) Back toric lens3) Bi-Toric lens4) Front toric lens

A. 1 onlyB. 1 and 3C. 2 and 4D. 1, 2 and 3

124. Which of the following may cause a soft lens to need to be replaced more often?A. Chemical disinfectionB. Enzymatic cleaningC. Heat disinfectionD. Nightly cleaning

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125. Which of the following is a preservative found in soft contact lens solutions?A. ChlorbutanolB. PolyquadC. Benzalkonium chlorideD. Benzyl alcohol

126. Which of the following hobbies and activities should be discussed with patients?A. Long periods of computer workB. Long periods of readingC. Long periods of drivingD. All of the above

127. Conventional daily wear soft contact lenses, properly cared for, should be replaced at least:A. QuarterlyB. YearlyC. Every two yearsD. When they hurt

128. Which of the following is a non-approved wetting solution that is quite safe for the patient to use?A. SalivaB. ToothpasteC. Dish soapD. None of the above

129. Which medication should not be used with soft contact lenses as it will turn lens brown?A. AntacidsB. EpinephrineC. DigitalisD. Insulin

130. If a soft contact lens becomes adherent to the cornea, the patient should:A. Irrigate the eye profusely with warm water until the lens becomes loose

B. Pinch the lens off the eye by placing the thumb and forefinger at 3 and 9 o'clock on the cornea and squeezing to break the suction

C. Irrigate the eye with saline or rewetting drops until the lens begins to move freely again

D. Use a DMV suction cup to remove the lens

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131. Poor RGP insertion or recentering techniques may result in:A. 3 and 9 o'clock stainingB. The lack of a fulcrum at 3 and 9 o'clockC. Arcuate stainingD. Coalesced SPK centrally

132. When can Johnny, a 12 year old new soft lens wearer, comfortably be sent home with new lenses?A. When the mom has worn for yearsB. When he can remove the lenses by himselfC. When he can insert and remove the lenses by himselfD. When he promises to remove the lenses daily.

133. The purpose of a combination wetting/soaking RGP solution is to:A. Maintain lens surface wettabilityB. Disinfect the lensC. Cushion the lens during insertionD. All of the above

134. Enzymatic cleaning of soft lenses is important in:A. Preventing the development of GPCB. Preventing the lens from shrinking and tighteningC. Maintaining the hydration of the lensD. All of the above

135. Which of the following statements about eye make-up is correct?A. Eyeliner should be applied to the inner margin of the eyelids behind the lashesB. Eyeliner and mascara should be replaced every 3 to 6 months to avoid

contaminationC. Mascara should be applied to the base of the lashes onlyD. Eye make-up should be applied before inserting contact lenses

136. Which of the following is not considered a normal adaptive response to soft lenses?A. Awareness of the lenses in the eyeB. Awareness of bright sunlightC. Slight itching sensationD. Lenses feeling "hot" in the late afternoon

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137. Which of the following statements is correct?A. If patients touch the tip of a solution container to their skin or eyelashes, they

should wash the tip with soap and waterB. If a soft contact lens dries out, it should be immersed in warm water until it softensC. Disinfecting solutions should be "topped off" nightly and changed weeklyD. Solution containers should always be capped after use to prevent contamination

138. Thermal disinfection of soft lenses:A. Extends the life of the contacts since it kills microorganisms better than chemicalsB. Can be done by boiling the lens case in a pot of water for one hour if a thermal

disinfection unit is not availableC. Is effective against acanthamoeba cysts and trophozoitesD. Does not require prior cleaning with a surfactant since it kills microorganisms so

effectively

139. Hydrogen peroxide care systems:A. Should not be used to disinfect FDA Group IV lensesB. Is more effective against viruses and fungi than most chemical disinfection

systemsC. Does not require a red tip on its container, since it does not cause permanent

damage if accidentally instilled into the eyeD. Takes a minimum of two hours to be decomposed into water and oxygen

140. Which of the following can NOT be used to measure the diameter of a rigid lens?A. Profile analyzerB. Measuring magnifierC. Diameter gaugeD. Shadowgraph

141. Use of a Wratten # 12 or Tiffen yellow filter is important in evaluating the fluorescein pattern of patients with RGP lenses because:A. Many patients are wearing lenses containing UV inhibitors that block fluoresceinB. There will be too much fluorescence if a filter is not usedC. 3 and 9 o'clock staining will not show up if the filter is not usedD. The filter will help to identify patients with corneal warpage

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142. If fluorescein evaluation reveals apical staining, it could be due to:A. A lens that is too flat and looseB. A lens that is too steep and tightC. Corneal edemaD. All of the above

143. Newly fitted extended wear patients should have their first recheck in:A. 24 hoursB. 3 daysC. 2 weeksD. 3 weeks

144. If an adapted contact lens wearer complains of a sudden onset of discomfort, the technician should suspect:A. A change in corneal curvatureB. Giant Papillary ConjunctivitisC. A damaged contact lensD. Tight lens syndrome

145. If an RGP lens fails to provide acceptable visual acuity, the fitter should first:A. Flatten the lens to cornea relationshipB. Have a sphero-cylindrical over-refraction

performed to see if the reduced acuityis due to residual astigmatism

C. Refit the patient with a soft lensD. Use a lens with a higher Dk/1L value

142. According to the FDA, disposable contact lenses that are removed nightly, should be discarded after:A. 1 weekB. 2 weeksC. 1 monthD. When they appear cloudy or hurt the patient

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147. Three and nine o'clock staining in RGP lens wearers can best be eliminated by:A. Reducing center and edge thickness and teaching the patient to blink completelyB. Adding a minus carrier to the lensC. Using preservative-free saline instead of RGP wetting/soaking solutionD. Using a single-cut rather than a multicurve lens design

148. Circumcorneal. injection in a soft lens wearer may be a sign of:A. Tight lens syndromeB. Solution sensitivityC. KeratitisD. All of the above

149. A technician can perform a preliminary evaluation of soft contact lens movement by:A. Observing the movement of the lens edge in relation to the position of a

conjunctival vesselB. Having the patient look up and blinkC. Observing movement and lens lag in upward and lateral gaze with a penlightD. All of the above

150. Which of the following statements concerning lens movement is not correct:A. A tight lens may cause blanching of the limbal vesselB. A tight lens may cause scleral indentationC. A loose lens may cause blurred vision immediately following the blinkD. A loose lens will be considerably more comfortable than a tight lens

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FOLLOW-UP VISITS WITH THE PATIENT

151. Which of the following modifications to a rigid gas permeable lens can not be made in the office?A. Blending of peripheral curvesB. Addition of minus powerC. Polishing lens surfaceD. Changing the base curve

152. In-office polishing of the anterior surface of a rigid gas permeable lens surface will provide many benefits to the patient. Which of the following is not a benefit of polishing the lens in the office?A. Cleaner lens surfaceB. Increased lens comfortC. Thinner lens edgeD. Removal of scratches on the lens surface

153. What is the most important feature of an in-office modification unit?A. Easy to cleanB. Variable speed motorC. It has a removable coverD. Manufacturer's warranty

154. If a patient with exophthalmic eyes due to thyroid disease requires a toric lens:1. It will be forcibly expelled from the eye due to the bulging eyeball2. It may dehydrate excessively due to the lid retraction and dry eye condition that

often accompanies thyroid disease3. Stability will be difficult to maintain since there are no lid forces to keep the lens in

position4. The "watermelon seed" principle will help to keep the lens in positionA. 1 and 2B. 2 and 3C. 1, 2, 3 and 4D. None of the above

155. Which of the following is not characteristic of corneal edema?A. Smoky visionB. Spectacle blurC. Increase in K readingsD. Peripheral flare

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156. Which of the following is not used when blending peripheral curves in the office?A. Slot gaugeB. Radius toolsC. Polishing compoundD. Suction cups or a spinner tool

157. The slit lamp illumination that gives an overall view of the cornea but limits detail is:A. Sclerotic scatterB. DiffuseC. Specular reflectionD. Oscillatory

158. When keratometric mires reflected off a soft contact lens are only clear when the wearer blinks, the lens fit is too:A. SmallB. LargeC. SteepD. Flat

159. Gross corneal edema, which manifests itself clinically as central corneal haze, is verified by the slit lamp using sclerotic scatter illumination. What specific technique does the examiner use to see this condition?A.The naked eye and an angle between the slit lamp beam and the eye of 90

degreesB. The blue cobalt filter of the slit lamp and an angle of about 45 degreesC. The green filter of the slit lamp with high magnificationD. High magnification and an angle between the beam and scope of 180 degrees

160. When inspecting the blend on the bevel of an RGP lens:A. The lens must be held so the reflection of light on the anterior surface of the lens

falls centrally on the lensB. The fluorescent tube should be behind and below the examinerC. An ideal blend should show a J-shaped or ski pattern in a smooth curveD. In order to get the reflection continuous to the edge of the lens it must never be

tilted

161. Diffuse central punctate staining is an indication of:A. A foreign body under the lensB. Lens flareC. Tight lensD. Excessively wide transitional zone

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162. Sandy returns to your office after being fit with soft contact lenses. She has complaints of the lenses becoming uncomfortable and burning as the day progresses. What might be the reason?A. The lens is too smallB. The lens is too flatC. The lens is too tightD. The lens is the wrong color

163. With a rigid contact lens in place, a fluorescein pattern shows a concentration offluorescein inferiorly and superiorly beneath the lens. Which one of the followingtypes of astigmatism is represented by this pattern?A. Lenticular astigmatismB. Residual astigmatismC. Against-the-rule astigmatismD. With-the-rule astigmatism

164. Mary is wearing a rigid gas permeable lens with a base curve of 43.50 D and a power of +2.75 D. She requires a -0.75 D sphere over this lens. If you wish to order her a new lens with a curve of 43.00 D, what will the new power be?A. + 1.50 DB. +2.00 DC. +2.50 DD. +3.00 D

165. FDA Group I soft lenses:A. Have a water content greater than 50% and a non-ionic surfaceB. Have a water content greater than 50% and an ionic lens surfaceC. Have a water content lower than 50% and a non-ionic surfaceD. Have a water content lower than 50% and an ionic lens surface

166. Which type of slit lamp illumination will allow you to determine corneal thickening, thinning and distortion and depth of foreign bodies or opacities in the cornea?A. Diffuse illuminationB. Optic sectionC. Retro-illuminationD. Conical beam

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167. Corneal edema is observed inferiorly under a prism ballast toric soft lens. What is the probable cause?A. Lens is too tightB. Corneal oxygen demand is too low forC. Lens is too looseD. Prism thickness is too great this lens

168. A soft lens has edge lift when observed on a cornea. How can this be corrected?A. Steepen the base curveB. Decrease the diameterC. Flatten the base curveD. Change the edge design

169. In evaluating a soft lens with either keratometry mires or retinoscopic reflex, you detect distortion immediately after the blink followed by clear mires. This is caused by:A. A steep fitting lensB. A properly fitting lensC. A flat fitting lensD. A tight fitting lens

170. Which of the following statements is correct?A. Extended wear soft lenses are extremely fragile and therefore a poor choice for

patients wishing to wear lenses on a daily wear basisB. FDA Group IV lenses have a negatively charged surface that attracts positively

charged tear film, proteins and lipidsC. Silicone acrylate RGP lenses contain a Teflon-like substance that gives their

Surfaces non-stick qualitiesD. Adding greater amounts of silicone to RGP materials increases both their oxygen

transmission and base curve stability

171. Which type of slit lamp illumination is used for observing tear break up time?A. Diffuse illuminationB. Optic sectionC. Direct illuminationD. Retro-illumination

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172. A non-wetting rigid gas permeable lens may cause:A. Hazy, filmy visionB. Lens awarenessC. Dryness or grittinessD. All of the above

173. Causes of lens flexure may include:1) Pressure exerted by the upper lid2) High Dk Lens material3) Apical clearance lens design4) Against the rule corneal toricity

A. 1 and 3B. 2 and 4C. 2 onlyD. All of the above

174. When evaluating fluorescein patterns, a special filter must be used with:A. Silicone acrylatesB. PolymethylmethacrylateC. Polymers with a UV blockerD. Hydroxyethyl Methacrylate

175. A normal fitting standard thickness soft contact lens will exhibit:A. Three point touch (apex and periphery)B. Apical clearanceC. Edge stand-offD. None of the above

176. Which of the following could cause a patient's rigid contact lens to displace frequently and pop out without cause?

1) Excessive posterior peripheral curve2) Insufficient peripheral curve2) Steep base curve relationship4) Flat base curve relationship

A. 1 and 4B. 2 and 3C. 1 onlyD. 2 and 4

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177. Among the following choices, which is the latest lens design for keratoconus?A. Soper designB. McGuire designC. Aspheric designD. Rose K design

178. A soft contact lens that is too loose may show all of the following EXCEPT:A. Edge stand-offB. Limbal compressionC. Excessive lens movementD. Distorted retinoscopy directly after blinking

179. A patient with a high degree of with-the-rule astigmatism fitted with a spherical rigid gas permeable lens will show touch:A. On the horizontal meridianB. On the vertical meridianC. On the oblique meridianD. On the residual meridian

180. A rigid lens showing apical touch is an indication of:A. A steep fitB. An intrapalpebral fitC. A flat fitD. An astigmatic fit

181. A rigid lens showing excessive apical pooling is an indication of-A. A steep fitB. An alignment fitC. A flat fitD. An astigmatic fit

182. Contact lenses that have a non-spherical back surface are called:A. Aspheric lensesB. Tricurve lensesC. Truncated lensesD. Spherical lenses

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183. A rigid lens showing central vaulting is indicative of:A. Apical clearance fitB. An alignment fitC. A flat fitD. None of the above

184. A rigid lens showing a band-shaped area of touch on the flattest meridian is an indication of:A. A steep fitB. An alignment fitC. A flat fitD. An astigmatic fit

185. When there is a slight pooling of fluorescein in the peripheral curve portion of a rigid lens, it indicates:A. A tight lensB. Slight edge liftC. A toric lensD. Slight lens warpage

186. REFER TO QUESTION #93. Once the correctly ordered lens has been dispensed, the rotational marks should settle at:A. Six o'clockB. 10 degrees clockwiseC. 10 degrees counterclockwiseD. None of the above

187. On a compromised cornea, such as a one that has undergone a corneal graft, what lens characteristic would be most beneficial?

A. High wetting angleB. High Dk/LC. Electric blue color for glareD. Lenticular design

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188. What two design changes might be helpful in centering a high riding myopic lens?1) Flattening the base curve relationship2) Myoflange Ienticular3) Hyperflange lenticular4) Prism ballast

A. 1 and 2B. 1 and 3C. 2 and 3D. 3 and 4

189. Rigid gas permeable lens flexure may be eliminated by:A. Reducing sagittal vaultingB. Increasing center thicknessC. Choosing a lower Dk materialD. All of the above

190. A low riding high plus lens on a 40.00 @ 180 / 40.75 @ 90 cornea could be corrected with:A. A myoflange lenticularB. A hyperflange lenticularC. A single cutD. A panafocal

191. Mike, a welder whose Rx is -6.00 +2.00 x 180, has been advised to trade his PMMA lenses of 20 years for a modality that allows more oxygen to the cornea. The first lens of choice would be:A. Soft spherical lensB. Low to mid Dk RGPC. High Dk RGPD. Aspheric lens

192. A technique for correcting a high riding rigid minus lens may be to use a:A. Flatter lensB. Larger lensC. Minus carrier lenticular lensD. Prism ballasted lens

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193. Advantages of a myoflange versus a single cut high plus lens include:1) Reduced center thickness2) Increased optical zone3) Reduced weight

A. 1 onlyB. 1 and 2C. 2 and 3D. 1, 2 and 3

194. To increase tear exchange with a rigid gas permeable lens, all of the following should be attempted EXCEPT.A. Reduce the overall lens diameterB. Flatten the peripheral curvesC. Increase the sagittal depthD. Decrease the optic zone

195. Which of the following polishing compounds should not be used with gas permeable lenses?A. Sil 02 CareB. SilvoC. Alox PGD. X Pal

196. In order to create a smooth blend between the intermediate and peripheral curve of the following contact, which radius tool should be used?

IPC 8.50 mm PPC 10.50 mmCPC 7.50 mm (45.00 D)A. 8.5 mmB. 9.5 mm.C. 10.2 mmD. 11.5 min.

197. To correct a flat fitting rigid gas permeable lens, you should:A. Enlarge the optical zoneB. Decrease the optical zoneC. Decrease the sagittal depthD. Decrease the lens diameter

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198. After building up her wearing time, Jennifer returned for an afternoon recheck after eight hours of lens wear. The lenses moved

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1. The answer is B

Antihistamines are beneficial when treating allergies and cold symptoms because they dry out the mucous membranes of the nasal passage. However, this may also lead to dehydration of the tear film.Antihistamines have also been known to slow down the blink rate and increase corneal sensitivity.

2. The answer is B

Photophobia refers to a sensitivity ("phobia”) to light ("photo"). Presbyopia is the condition that results when patients are no longer able to focus on objects at a near point.Pannus is the invasion of blood vessels onto the cornea. Ptosis is a drooping of the upper eyelid.

3. The answer is C

Against-the-rule astigmatism is present when the keratometer readings are steeper in the horizontal meridian (42.50 @ 180) than in the vertical meridian (40.50 @ 90).

4. The answer is C

The normal cornea is devoid of blood vessels. To provide metabolites, the cornea is nourished by diffusion of nutrients and oxygen by the aqueous humor, tears and vascular blood vessels in the limbus.The orbicularis occuli is a muscle in the eyelid whose primary function is lid closure.

5. The answer is A

Presbyopia is the gradual loss of accommodation due to the hardening of the crystalline lens that takes place as a person ages.

6. The answer is C

The radiuscope will measure the base curve of a rigid contact lens. The corneoscope and keratometer will give important information about the surface of the cornea. Only the slit lamp (or biomicroscope) can provide simultaneous information about the cornea, lids, conjunctiva, lashes, contact lens surface and fit.

7. The answer is C

The pre-corneal tear film is composed of lipid, aqueous and mucin layers. The lipid layer is traditionally thought of as most anterior (front) while the mucin layer is most posterior (back).

8. The answer is A

To transpose a prescription from plus to minus cylinder, first add the amount of cylinder to the sphere power: -4.50 + (+1.25) = -3.25Then change the sign of the cylinder power from plus to minus: +1.25 becomes - 1.25Finally, add or subtract 90 degrees from the cylinder axis: 94 - 90 = 4

9. The answer is B

Values higher than 7.4 are considered relatively alkaline, whereas values lower than 7.4 are considered relatively acidic.

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10. The answer is D

Patients should always be directed to follow the manufacturer's guidelines and not try to cut comers by leaving lenses in any solution for less than the recommended time. While overnight is longer than recommended and would not pose a problem for most patients, they should always be given very specific guidelines for time.

11. The answer is D

The cornea is exposed to the atmosphere, which contains 21% oxygen. Through a process known as diffusion, oxygen from the atmosphere dissolves into tears where it can be utilized by the corneal epithelium.

12. The answer is A

Patients are amblyopic when they are not able to attain 20/20 vision with an eye that has not experiencedany disease or trauma. Aniridia is the absence of an iris. Astigmatism refers to a refractive error in whichlight rays do not focus in a single point. Aphakia is the absence of the crystalline lens.

13. The answer is C

By placing a -1.00 D lens over the aperture of the keratometer, you can extend the low end range from 36.00 D to 30.00 D.

14. The answer is C

Before the patient is seated in the keratometer, the examiner should focus the eyepiece.This is particularly important if you are not the only person using the keratometer during the day.

15. The answer is A

Lenticular astigmatism is present when there is significantly more astigmatism in the patient's refraction (2.50 D) than on their corneal surface (0.50 D). In this case, the astigmatism is not represented on the cornea and is most likely found in the crystalline lens.

16. The answer is D

All of the listed signs are normal physiological changes as we become older.

17. The answer is C

To transpose a prescription from plus to minus cylinder, first add the amount of cylinder to the sphere power. +1.50 + (+1.00) = +2.50Then change the sign of the cylinder power from plus to minus: +1.00 becomes -1.00Finally, add or subtract 90 degrees from the cylinder axis: 75 + 90 = 165

18. The answer is B

The pre-corneal tear film provides a smooth optical surface for the cornea. This is maintained by the blinkmechanism, further providing metabolites (I.e.. oxygen) to and from the cornea as well as removing wasteproducts such as C02 and dead epithelial cells. The endothelium receives its oxygen from aqueous humorwithin the anterior chamber. Limbal hyperemia is redness from engorged blood vessels in the limbal area.

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19. The answer is C

Memorize the layers in order--this is a MUST.

20. The answer is A

The corneal endothelium provides the pumping mechanism of the cornea to expel fluidfrom the tissue and maintain corneal transparency. Bowman's membrane is an acellular layer, which provides strength to the cornea. The epithelium is the outermost layer of the cornea and only plays a minor role in corneal metabolism. The basal membrane is a basement membrane, which provides an attachment surface for the epithelium to adhere to Bowman's membrane.

21. The answer is B

Typically fluorescein will remain on the cornea for 10 - 12 seconds before it begins to break-up and dry spots appear. Less than seven seconds is considered a short break up time and may limit the success of contact lens fitting.

22. The answer is C

Arcus senilus consists of cholesterol deposits in the corneal periphery and does wt affect contact lens wearing. A dellen is a depressed area of compromised epithelial tissue on the cornea, which stains due to lack of wetting from the pre-corneal tear film. It is generally found adjacent to an elevated area.Neovascularization is the abnormal growth of new blood vessels into the cornea. Fuch's dystrophy is a corneal endothelial dystrophy affecting the central cornea.

23. The answer is A

Keratitis sicca is a severe dryness of the cornea. This leaves the cornea at risk. exposing it to complications related to secondary infections. Loss of eyelashes or contact lenses and steep corneas are not related to keratitis sicca.

24. The answer is A

Aphakia is the absence of the crystalline lens.

25. The answer is B

Anisometropia is present when the refractive errors of a patient's two eyes are so different from one anotherthat retinal images of disparate sizes result. Because of the different sizes, fusion of the two images may notoccur.

26. The answer is A

A patient's depth perception (stereopsis) will be compromised if fitted with spectacles.An IOL (intraocular lens) is used for aphakia. Scleral rigid lenses are also impractical and rarely used today.

27. The answer is A

The vertex distance correction is usually derived from a standard table. In the conversion of a prescriptionfrom the spectacle plane to the corneal plane, additional plus power is needed.

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28. The answer is A

A lensometer measures power. A diameter gauge measures diameter. A thickness gauge measures thickness.

29. The answer is D

A Burton lamp evaluates fluorescein patterns in the absence of a slit lamp. A Con-Ta-Chek is an attachment to the keratometer that enables one to read the base curve in the absence of a radiuscope. A topogometer is also an attachment for the keratometer and is used to define the corneal apex.

30. The answer is B

The range of the keratometer is 36.00 D to 52.00 D. To extend the range above 52.00 D, a +1.25 D lens is used.

31. The answer is B

Photophobia, burning sensations and feelings of grittiness can all be attributed to dry, low oxygen environments. A chalazion is an inflammation of a meibomian gland and is not related to dryness.

32. The answer is D

People in most occupations can successfully wear contact lenses as long as their eye care provider's instructions are followed in terms of wearing time, care handling, replacement schedules, the use of safety glasses and follow-up. The myth that arc welders cannot wear soft contact lenses because the contacts can become fused to the cornea, has been thoroughly dismissed.

33. The answer is A

While prolonged rigid lens wear, prolonged soft lens wear and irregular corneal astigmatism may all cause mire distortion, the mire distortion will remain constant. Of the choices listed, only the tear film results in transitory mire distortion which can be cleared up if you ask the patient to blink.

34. The answer is A

In against-the-rule astigmatism, the cornea has a vertical ellipsoidal shape. This puts the long, flat meridian at 90 degrees and the short, steep meridian at 180 degrees.

35. The answer is D

Dry eyes with rapid tear film break-up time will cause the keratometer mires to blur and appear irregular soon after a blink, as the tear film breaks up. Mucoid secretions will create an irregular surface on the cornea. Patients with keratoconus have irregular astigmatism and therefore irregular mires, as do patients with contact lens induced corneal warpage.

36. The answer is B

Lid attachment RGP fits should show a thin, even edge-to-edge layer of fluorescein stained tear film that exhibit alignment or slight apical feathering as well as less than 180 degrees of bearing in themid-periphery to allow for a good tear exchange with each blink. Choice A, apical clearance with 360 degrees of bearing in the mid-periphery indicates a steep, tight fit with complete seal-off and no tear exchange. Choices C and D are indicative of an excessively flat fit.

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37. The answer is C

Choice A, failure to close the lids completely when blinking would result in 3 and 9 o'clock staining. Choice B would cause apical staining. Choice D would usually cause a very fine, diffuse superficial punctate keratitis (SPK) from limbus to limbus.

38. The answer is D

The Schirmer I test is done without anesthesia and a patient with normal tear output should wet at least 15 mm of the strip in 5 minutes. Choice C refers to a test of tear quality, no quantity, that is timed and observed with the patient seated at a slit lamp.

39. The answer is B

Choice A refers to the Break-up time (BUT) test done with fluorescein to evaluate tear quality. Choice C is not correct because some patients, even with an anesthetized eye, produce a large volume of reflex tears in response to the paper strips in the eye, but under ordinary circumstances have greatly reduced tear output. Choice D is incorrect because xerosis is a dry eye condition, not one in which a large volume of tears is produced.

40. The answer is B

Rose bengal will cause a dense, confluent staining with a uniformly intense red color in a pathologically dry eye and a discrete punctate conjunctival stain in a marginally dry eye, since it binds strongly and selectively to devitalized cellular components. Schirmer testing, on the other hand, tests tear output and does not allow evaluation of tissue damage from dryness. Fluorescein is used to stain tears, not ocular tissues, in the evaluation of RGP lens fits.

41. The answer is C

Rose bengal is attracted to devitalized cells; it is not used to stain the tear film. Break- up-time (BUT) testing is done by instilling fluorescein, having the patient blink once to spread the fluorescein across the cornea and timing the interval between the blink and the development of the first dry spot (tear break-up) on the cornea. Generally, a BUT of greater than 10 seconds is needed for successful contact lens wear.Choice D is incorrect because testing is done at the slit lamp, not the keratometer.

42. The answer is D

Choices A and C are incorrect because preservatives are bacteriostatic, not bactericidal. They do not kill microorganisms, but only prevent them from multiplying in solution bottles after they are opened.Mercury compounds are rarely used anymore, due to their high rate of sensitivity.

43. The answer is B

Prism in contact lenses is generally added to ensure proper orientation of a toric or bifocal lens and is usually ineffective in correcting motility problems, especially those of a horizontal nature. Therefore, the patient may experience diplopia when wearing contact lenses and may need piano glasses with prism ground into them to wear over the contacts. Nystagmus is a neurologic and often congenital ocular condition in which the eyes constantly oscillate and is unrelated to most motility problems.

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44. The answer is A

Contact lenses require myopic patients to use more accommodation and convergence than spectacles. Patients who are approaching presbyopia may find that their near vision is still adequate with glasses but cannot see small print when fit with contact lenses. Choice B is irrelevant to patients who wear contact lenses as the lenses fit directly on the cornea and cannot be moved closer to or further from the eye.Moving spectacles further from the eye will increase vertex distance and help near vision. Choice C is a means of allowing the presbyopic patient to read by fining one eye for distance and the other for near vision. Choice D is incorrect, since less accommodation is needed to see the computer, which is further from the eye, than to read.

45. The answer is C

Vertex distance must be taken into account when spectacle power is +4.00 D. In the conversion of a prescription from the spectacle plane to the corneal plane, additional plus power is needed. Thus, less minus power is required for a high myope's contact lenses compared to their spectacle prescription. Additional plus power is needed for a high hyperope's contact lenses compared to their spectacles.

46. The answer is D

The patient's refractive astigmatism is 0.25 diopters, which is essentially a spherical correction. A soft spherical lens will correct this although corneal astigmatism is present.

47. The answer is A

An intrapalpebral fit is a small diameter, steep fitting lens designed to center between the upper and lower eyelids. The other choices are either large diameter or flat fitting lenses.

48. The answer is B

A soft spherical lens would not correct the lenticular astigmatism. RGP lenses tend to decenter onagainst-the-rule corneas. There is not enough corneal toricity for an RGP lens with toric curves on the back surface to stabilize.

49. The answer is D

Silicone is 100% oxygen permeable and is responsible for increasing the oxygen permeability of many RGP materials.

50. The answer is D

While it may be interesting as a matter of conversation, the type of lens that the sister is wearing is not critical information for a new patient's follow-up visit.

51. The answer is A

Fluorescein is a valuable tool in evaluating the lens to cornea relationship of a rigid gas permeable lens. A special type of fluorescein (fluorosoft) should be used to evaluate the fitting relationship of a soft contact lens but will not be useful in evaluating the parameters of that lens. Fluorescein will not add any information when observing corneal vascularization or performing over-refractions.

52. The answer is A

Increasing the overall diameter, increasing the optic zone diameter as well asincreasing the sagittal depth will all decrease the movement of the rigid gas permeable lens. Decreasing the overall lens diameter will loosen the fit and increase the movement of the lens.

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53. The answer is B

Decreasing the lens diameter or flattening the base curve will only serve to loosen the lens to cornea relationship and increase the possibility of the lens decentering. Increasing the center thickness will have no bearing on lens centration. Increasing the overall diameter of the lens, however, is one way to improve lens centration.

54. The answer is C

Increasing the overall lens diameter and steepening the base curve will tighten the lens. This will tend to decrease the movement of the soft lens even further. Adding minus power to the soft lens will not have any effect on the fit and will decrease the patient's best vision. By flattening the base curve, the fit will be loosened and movement will be increased.

55. The answer is D

A soft toric lens is not indicated in this instance. A spherical rigid gas permeable lens would result in residual astigmatism. With an increased center thickness, corneal astigmatism will be corrected, which may actually blur the patient.

56. The answer is B

This minus carrier design increases edge thickness and enables a low-riding high plus lens to center better.

57. The answer is C

Since the astigmatism is lenticular and is not found on the cornea, a spherical rigid gas permeable lens willnot mask the astigmatism since it is lenticular. There is not enough corneal astigmatism to stabilize a backsurface toric lens. A spherical soft lens will not be able to correct this amount of astigmatism.But, a soft toric lens will be able to correct all of the astigmatism.

58. The answer is B

To determine the Rx of a rigid gas permeable lens, first put the Rx in minus cylinder form: - 3.00 +1.00 x90 becomes -2.00 -1.00 x 180Next, drop the cylinder. When fitting a lens "on K” order the sphere power corrected for vertex distance, when the Rx is in minus cylinder: -2.00

59. The answer is C

Truncating the lower edge of the lens would help to provide a flatter, thicker surface to interact with the lower lid, enabling the lens to rest in the proper position.

60. The answer is A

When applying the sphero-cylindrical over-refraction to a spherical rigid gas permeable lens, first put the over-refraction into minus cylinder form.piano +1.50 x 95 becomes +1.50 -1.50 x 5.Add the spherical component to the existing spherical component (-2.00 plus +1.50 becomes -0.50) Then simply tag on the cylindrical portion of the over-refraction.

61. The answer is C

When applying the results of an over-refraction to a soft lens, first put the over-refraction in minus cylinder.Men determine the spherical equivalent and add this to the existing power.

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62. The answer is C

A profile analyzer's function is to aid the contact lens professional in evaluating the quality of the peripheral blends of an RGP lens.

63. The answer is A

To compensate for the rotation of a diagnostic soft toric lens, the "LARS" principle tells you to add the number of degrees of rotation if it rotates to the practitioner's left and subtract the amount of rotation if it rotates to the practitioner's right. In this case, the lens rotates to the right and the degree of rotation must be subtracted from the original axis.

64. The answer is B

A soft spherical lens will not correct the astigmatism present in this patient's refraction so it will not provide adequate vision. A soft toric lens, spherical and aspheric rigid gas permeable lens will all correct the astigmatism.

65. The answer is D

Fluoro silicone acrylate is the only rigid lens material listed. The other lenses are soft and are often a poor choice for patients with keratoconus. Although soft lenses may be used in the early development of keratoconus, these flexible soft materials cannot correct irregular astigmatism which is so characteristic of keratoconus.

66. The answer is A

Most cases that call for prism ballasting of an RGP lens will require between 0.75 and 1.50 D of prism.

67. The answer is D

Aspheric, McGuire and Soper lenses are recognized modalities for the management of keratoconus. Tangent Streak lenses are used in the treatment of presbyopia.

68. The answer is C

When applying the results of an over-refraction to a soft lens, transpose the over-refraction to minus cylinder. Then determine the spherical equivalent (-1.25 D in this case) and add this to the existing power.

69. The answer is D

Intrapalpebral lenses are designed to center between the upper and lower eye lids. To achieve this positioning, an on K or steeper than K base curve is designed with diameters of 9.0 mm or smaller.

70. The answer is A

"Lid attachment" lenses are designed to fit with the upper edge of the lens positioned under the upper eye lid. To achieve this positioning, a flatter than K, larger diameter (over 9.0 mm)is generally used.

71. The answer is B

All of the other lens designs listed are simultaneous vision lenses.

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72. The answer is A

The base curves will parallel the K readings and the power in the lens will properly correct the astigmatism. A spherical lens design will rock on the 180 degree meridian causing discomfort and the chance of lens displacement or expulsion.

73. The answer is D

Corneal topography, lid shape, lid positioning and lid tightness should all be considered in the pre-fit evaluation and selection of lens type.

74. The answer is D

A bitoric lens design will provide the best lens orientation on against-the-rule corneal topography.The other answers are incorrect because the spherical base curves will not contribute to proper positioning of the lens on the against-the-rule cornea.

75. The answer is B

The base curve will parallel the spherical cornea and the prism ballast will position the cylinder in the lenson the axis of the Rx. A bitoric lens' base curves will create an additional cylindrical effect and will rotatecreating fluctuating vision because there is no corneal toricity to keep the lens in position. A spherical lenswill not correct the residual cylinder in the refraction. A Soper cone lens design is used for keratoconus.

76. The answer is B

A toric rigid lens should always be recorded with the flat meridian first and the steep meridian second. The total power in each meridian is written to correspond respectively.

77. The answer is D

A hyperflange would only be appropriate to consider for a high minus lens. All of the others are very important to the successful fitting of an aphakic RGP contact lens.

78. The answer is A

Monocentric and crescent lenses have bifocal segments. A juxtapositioned lens simply means that the lens is not positioned correctly but has nothing to do with the lens design.

79. The answer is B

A lenticular (myoflange) lens is best suited for aphakic patients with corneal curvatures flatter than 45.00 D, large palpebral fissures and flaccid lower lids.

80. The answer is C

The general rule of thumb for determining initial soft lens diameter is to choose a lens 2.0 mm larger than the cornea. This will result in 1.0 mm on either side of the cornea and will aid lens centration.

81. The answer is B

A single cut aphakic lens is best suited for patients with small apertures and steep corneas.

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82. The answer is B

The power is on the posterior surface of a spin-cast soft lens and thus changes in power will change the fit of the lens. In a lathe-cut lens the power is on the front surface and changing power does not alter the fit.

83. The answer is C

Due to the irregular astigmatism secondary to keratoconus and penetrating keratoplasty (PKP), reliable K readings are not obtainable. Therefore, trial fitting is the most practical means of lens fitting.Molded impressions (used for scleral lenses) are rarely used today.

84. The answer is A

Due to the increased edge thickness of a high minus lens, it will frequently "catch" under the upper lid causing it to ride high.

85. The answer is A

Aspheric lens designs are the only bifocals listed which do not have independent near and distant zones. The others listed have separate sections for distance and near vision.

86. The answer is D

A soft toric lens will correct residual and lenticular astigmatism, as well as low to moderate amounts of corneal astigmatism. Custom made soft toric lenses have also been effective in correcting higher degrees of astigmatism with great success.

87. The answer is C

Ideally, a keratoconus lens should center well with good movement and a 3 mm feather touch over the apex of the cone. It is not advisable to attempt to flatten the apex.

88. The answer is C

Therapeutic lenses should be fit with minimal movement in corneas with broken epithelial surfaces such asin recurrent erosions. A lens with normal movement should be fit when the epithelium is intact as indicatedin the other dystrophies.

89. The answer is B

Patients who are heavy depositors will benefit from frequent replacement of their lenses. Thus, the majority of patients will do well with soft disposable lenses worn for daily wear. Extended wear lenses would create a "time bomb" on the eyes of patients who are heavy depositors, and may lead to the exacerbation of GPC and possible additional complications, including infections, corneal ulcers and hypoxic complications.

90. The answer is D

The concentric, aspheric and diffractive lens designs are all "simultaneous" image lenses since a distance and near image are projected simultaneously onto the retina. A translating lens (Le. segmented) must move upwards for near vision. When properly fitted, this lens design will project "alternating" images on the retina-one for distance, one for near.

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91. The answer is A

These designs are utilized by various soft lens manufacturers to maintain lens positioning.

92. The answer is B

To achieve optimal corneal coverage without causing conjunctival injection, the lens of choice would be 2.0 mm larger than the HVID.

93. The answer is D

When a diagnostic soft toric lens rotates clockwise (LEFT from the six o'clock position), the amount of rotation is ADDED to the refractive cylinder axis. If the diagnostic lens rotates counterclockwise (RIGHT), the amount of rotation is SUBMACTED from the refractive cylinder axis. Calculations should be based on the patient's refractive axis not on the axis of the diagnostic lens.

94. The answer is C

Fluoro-silicone acrylate (FSA) materials contain a fluorinated monomer similar to Teflon (R) that makes them glide more smoothly in the eyes and shed deposits with each blink. Choice A is incorrect because high Dk RGP lenses contain more silicone, which decreases their stability and deposit resistance. Choice B is incorrect because the fluorinated materials are resistant to protein build up. Choice D is incorrect because silicone/acrylate materials have a negatively charged surface that attracts lipid and protein deposits.

95. The answer is D

Choices A and B arc incorrect because there is no corneal toricity to stabilize a back surface toric or bitoric RGP lens. Choice C is incorrect because a soft spherical lens, although it may fit well, will not be able to correct or mask two diopters of lenticular astigmatism. A front surface toric RGP lens that is prism ballasted to maintain alignment of the cylinder with the meridian of the patient's refractive astigmatism should provide acceptable correction of this patient's refractive astigmatism.

96. The answer is A

This patient has against-the-rule astigmatism and the cornea has a vertical ellipsoidal shape. When an RGP lens is placed on this type of cornea, a fulcrum or bearing point is established at 6 and 12 o'clock in the vertical meridian. There are no bearing points in the horizontal meridian to help guide the lens in its downward excursion and the lens will tend to decenter nasally or temporally with the blink. Choice B is incorrect because in most cases a lid attachment, alignment fit will not be attainable in patients with two diopters of against-the-rule astigmatism. Choice C is incorrect because the mismatch between the base curve of the lens and the corneal curvature should preclude adhesion.

97. The answer is A

This design reduces the edge thickness of a high minus lens increasing patient comfort and allowing the lens to center better.

98. The answer is B

To compensate for rotation of a diagnostic soft toric lens, add the amount of rotation if it rotates to the your left and subtract the amount of rotation if it rotates to the your right. The degrees of rotation are subtracted from the patient's refractive axis not the axis of the diagnostic lens. In this case, the lens rotates to the left and the degrees of rotation are added to the refractive axis.

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99. The answer is B

If you flatten the base curve (42.00) but increase the diameter (10.0) you will not effectively change the lens to cornea relationship. If you increase the base curve (43.00 and 43.50) and do not significantly reduce the lens diameter, you will steepen the lens to cornea relationship. Only "B" will flatten the lens to cornea relationship because it reduces the lens diameter without altering (steepening) the base curve.

100. The answer is A

Phoropters, spectacles and trial lenses are all specified in back vertex power. Therefore, to maintain consistency, most contact lenses are also specified in back vertex power. Front vertex power should always be indicated if it is used, especially in a high plus lens since it will differ significantly from back vertex power.

101. The answer is B

According to the ANSI standards (Z80.2 - 1989), the tolerance for the overall diameter of a contact lens is+ / - 0.05 mm. ANSI standards have been developed to maintain quality in the contact lens industry. It is important to have an understanding of the ANSI guidelines.

102. The answer is D

The slot gauge, shadowgraph and measuring magnifier will all enable the practitioner to verify the overall lens diameter of a rigid gas permeable lens. The radiuscope is an instrument that will measure the base curve of a rigid lens.


By placing the back (posterior) surface of the rigid gas permeable lens against the lens stop, the reading that results will be in back vertex power.


An ophthalmometer, another name for the keratometer, cannot measure the listed parameters. The profile analyzer evaluates the peripheral curve blends and the radiuscope measures the base curve of the rigid contact lens. The measuring magnifier is the only instrument that will measure the parameters listed.


All of the listed instruments show that a rigid contact lens has blends. However, the only instrument that can adequately assess the quality of the blends between the peripheral posterior curve (PPC), intermediate posterior curve (IPC) and the central posterior curve (CPC), is the profile analyzer.


A keratometer measures the corneal curvature. A profile analyzer measures the peripheral curves (blends) and a v-groove gauge measures the diameter of a rigid contact lens.


According to the ANSI standards (Z80.2 - 1989), the tolerance for the power of a contact lens under+ /- 10.00 D is + / 0.12 D.

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Verification should show:Lens type Radiuscope LensometerSpherical One base curve Spherical RxWarped Two base curves Spherical RxFront Toric One base curve Sphero-cylindrical RxBack Toric Two base curves Sphero-cylindrical RxBi-Toric Two base curves Sphero-cylindrical Rx

109. The answer is C

A keratometer will measure the base curve of a lens with an attachment known as a con-ta-check; however,a radiuscope is most frequently used. A thickness gauge will measure the center thickness of a contact lens.A Burton lamp evaluates the fluorescein pattern similar to a slit lamp.


When a patient spends a great deal of time reading or any other activity in which they are intently staring at an object (watching TV, driving, etc.) they may experience some discomfort as their blink rate drops and new tears are not exchanged for old tears underneath the lens.


Choice A would be correct only for patients who have already gone through the sequence of follow-up care recommended for new contact lens wearers as outlined in choice C. Choice B involves an excessive number of follow-up visits which can be inconvenient for the patient and impractical for the practitioner. If the GPC is so severe that the patient must return every 2 weeks, they are not yet ready to be refit with contact lenses. Choice D is incorrect because it is rare that a penetrating keratoplasty results in a spherical cornea and post-graft patients tend to be more difficult to fit with contact lenses. One must also watch the graft/host junction closely for problems.


All of the other lens materials are recommended to be cleaned weekly with an enzymatic cleaner.


The 3+ distortion is most probably due to irregular astigmatism and is best corrected with a rigid lens option.


The power of a high plus lens will always measure a larger numerical value in back vertex power (BVP) when compared to the reading in front vertex power (FVP).


Chlorbutanol and benzalkoniurn chloride are antimicrobial agents used in rigid lens disinfectants. Thimerosal is a preservative used in soft contact lens care products but has a high ocular sensitivity rate.

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It is important to see patients who sleep in their lenses as soon as possible after awakening in order to detect corneal edema. The edema resolves as oxygen is transmitted through the lens in an open-eye environment and will probably be gone if the follow-up visits are scheduled later in the day. It is important to see all extended wear patients the morning after they sleep with their lenses for the first time to detect any adverse reactions, even if the patients have been long-term successful wearers of daily wear lenses.


Every 0.05 mm of radius equals approximately 0.25 diopters. The lens ordered was 43.00 D, but was received as a 42.50 D.


There is a high probability that this patient has keratoconus, typified by the steep keratometer readings, the high degree of cylinder and the irregular retinoscopy reflexes.


The refraction is already in minus cylinder form, so there is no conversion needed. The cylinder/axis is dropped leaving the contact lens professional to deal with the -3.50 D of the sphere power. Fitting the lens one half diopter steeper than flat K requires adding a half diopter of minus to the sphere which would result in a final lens power of -4.00 D.


While many extended wear materials have FDA approval for 30 days of continuous wear, a maximum of 7 days of continuous wear has been recommended.


Thimerosal is an organic mercurial compound.


The first step is to convert the prescription to minus cylinder which results in-3.00 -2.00 x 180. The cylinder and axis are dropped which leaves -3.00 sphere. When a lens is fit on K, no compensation is needed for the resulting tear film so the lens power remains -3.00 D.


A front toric lens will show a spherical posterior curve on the radiuscope and a sphero-cylindrical Rx on the lensometer.


Heat disinfection will coagulate surface deposits onto the lens often causing it to need more frequent replacement.


All of the other preservatives listed are used in rigid lens solutions. They may build up in high concentration in the matrix of a soft lens and cause corneal damage.

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Patients who spend a lot of time on attention-intensive tasks such as computers, reading or driving, tend to have a reduced blink reflex. This may result in drying of the lens, discomfort and fluctuating visual acuity.


Durable soft contact tenses will need greater care than their disposable or frequent replacement counterparts. When properly cared for, they should be replaced yearly.


Patients should never be allowed to use any solution that has not been approved for that specific use!


Epinephrine, found in nasal sprays and medications used in the treatment of glaucoma, has been known to turn a soft contact lens brown.


A lens adheres to the cornea if it is not wet enough or salty enough. Either way, irrigation with saline solution or rewetting drops formulated for soft lens wearers will restore the salt and water content of the lens and allow it to move freely again. Choice A is incorrect because water (or any hypotonic solution) will increase lens adhesion. Choice B is incorrect because pinching an adherent lens off the cornea will remove epithelial tissue and may cause a painful abrasion. Choice D is incorrect because a DW suction cup will not remove a soft lens.

13 1. The answer is C

Since the edge of an RGP lens is curved, it will damage epithelial cells in an arcuate pattern if it is inserted or recentered incorrectly. Three and nine o'clock staining is related to peripheral desiccation and can be caused by lid gap, incomplete blinking and failure to resurface the areas just outside the lens edge with tear film mucin with each blink. Lack of a fulcrum (or bearing point) for an RGP lens is unrelated to lens insertion or recentering techniques. Choice D, coalesced SPK (superficial punctate keratitis) centrally, could be due to excessive apical bearing from a flat lens, central corneal clouding from a tight, steep lens or a lens that supplies insufficient oxygen to the cornea. It could also be caused by a foreign body that has been trapped centrally under the lens.


New lens wearers should never be allowed to leave the contact lens professional's office until they can demonstrate successful lens insertion and removal.


All combination wetting/soaking solutions meet FDA criteria for lens disinfection in a 4 hour soak time. The "wetting agents" in these solutions help to cushion the lens on insertion and help tears to spread evenly across the lens surface.


Enzymatic cleaning will remove protein from the surface of a soft lens which can contribute to the development of Giant Papillary Conjunctivitis (GPC). These deposits are also responsible for the soft lens becoming dehydrated and tightening on the patient's eye.

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Eye make-up preservatives will usually prevent or retard bacterial growth in these products for 3 to 6 months. After that, they may become contaminated and cause eye infections. Choice A is incorrect because eyeliner should be applied only outside the lash margin. Choice C is incorrect because mascara that is applied at the base of the lashes will clog the outlets of the meibomian glands. Choice D is incorrect because if eye make-up is applied before contact lenses are inserted, the lenses may pick up particles of mascara and eyeliner. Eyeshadow may transfer to the fingers and then to the lenses during insertion. It is best to insert the contact lenses and then apply any eye make-up.


Lenses feeling "hot" in the late afternoon may be an indication that the lens may be too tight. All of the other choi

NCLE - Optical Nerd · 2020. 7. 24. · 4. NCLE Preparation Exam. 16. Ocular signs, of aging...

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Transcript of NCLE - Optical Nerd · 2020. 7. 24. · 4. NCLE Preparation Exam. 16. Ocular signs, of aging...