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65 Cards in this Set
- Front
- Back
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Which of the following will aid the fitter in arriving at the correct contact lens diameter? |
D) All of the above.
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The advantages that contact lenses have over spectacle lenses in a person with aphakia include:
A) Less magnification B) Less peripheral aberration C) Increased visual field D) No heavy glasses kept in adjustment E) All of the above |
E) All of the above.
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What basic lens types are used in aphakia?
A) Single cut lenses B) Lenticular C) Tangent lenticular lens D) Minus carrier lens E) All of the above |
E) All of the above.
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Given the following Rx for a patient's right eye, +11.00+1.00x20, V.D. 12mm; what power would be needed in a rigid contact lens fit on K.
A) +11.00 B) +12.00 C) +13.00 D) +14.00 |
D) +14.00
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The best method to fit a conical-cornea with rigid contact lenses is by:
A) Keratometer readings B) Topogometer readings C) Trial lenses D) Eye impression E) None of the above |
C) Trial lenses
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All of the following are symptoms of a loose fitting rigid lens except:
A) Lid sensation B) Feel lenses move C) Constant awareness D) Burning |
D) Burning
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Prism ballast lenses are used:
A) To reduce lens rotation B) For front surface cylinders C) For some bifocals D) All of the above |
D) All of the above
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Bitoric lenses are:
A) Used when there is a great deal of corneal astigmatism B) Used on spherical corneas C) Used for bifocal fittings D) Used to reduce edema |
A) Used when there is a great deal of corneal astigmatism
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Which of the following curvatures indicates the flattest base curve?
A) 7.60mm B) 37.00 diopters C) 48.00 diopters D) 8.20mm |
B) 37.00 diopters
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If the base curve of a contact lens was ordered as 7.80mm and the lens received measures 7.85mm,
A) It is 0.25 D flatter than the lens ordered B) It is 0.25 D steeper than the lens ordered C) It is 0.50 D flatter than the lens ordered D) It is 0.50 D steeper than the lens ordered E) None of the above |
A) It is 0.25 D flatter than the lens ordered
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When checking the base curve of a rigid contact lens, the tolerance should be:
A) +/- 0.05mm B) +/-0.02mm C) +/-0.25mm D) +/-0.50mm E) None of the above |
B) +/-0.02mm
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When checking the fit of a PMMA lens using follow-up keratometry:
A) The cornea should be within +/-0.50 D from the original reading B) The cornea should be within +/-1.00 D from the original reading C) The cornea should be within 0.30mm from the original reading D) All of the above E) None of the above |
A) The cornea should be within +/-0.50 D from the original reading
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If the base curve of a contact lens is 7.50mm, the posterior peripheral curve would be:
A) 7.40mm B) 45.00 D C) 46.00 D D) None of the above |
D) None of the above
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A contact lens wearer may experience edema of the cornea because of:
A) Poor optics of the lens B) Over-correction of the lens C) Under-correction of the lens D) None of the above |
D) None of the above
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The following modifications may be made to a PMMA lens:
A) Flattening the peripheral curves B) Adding more peripheral curves C) Adding minus power to a contact lens D) Removing scratches from the surface E) All of the above |
E) All of the above
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An instrument not generally employed in the fitting of contact lenses is the:
A) Keratometer B) Slit lamp C) Lensometer D) Keratoscope E) Trial lenses |
C) Lensometer
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Before using any ophthalmometer, it is necessary to:
A) Focus the mires B) Focus the eye piece C) Lock the instrument into position D) Rotate the drum |
B) Focus the eye piece
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The secondary curve of rigid contact lens is usually:
A) Steeper than the C.P.C. B) 3 to 6 diopters C) 1/2 to 1 diopters flatter than the base curve D) All of the above |
B) 3 to 6 diopters
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The term "haptic lens" is often used in reference to:
A) Corneal lens B) Cosmetic lens C) Truncated lens D) Scleral lens E) None of the above |
D) Scleral lens
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The transition zone between the cornea and the sclera is called the:
A) Optical zone B) Negative zone C) Limbus D) Tertiary curve |
C) Limbus
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Edema might be detected during:
A) Post-wear refraction B) Follow-up keratometry C) Slit lamp examination D) All of the above |
D) All of the above
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If the base curve of a contact lens measures 45.00 diopters, its radius of curvature is:
A) 7.40mm B) 7.50mm C) 7.60mm D) 7.70mm |
B) 7.50mm
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If a PMMA lens measures 8.8mm, is -6.00 D and rides high because of the upper lid, what modification could we make on the lens to better center it?
A) Blend the junction B) Increase the size C) Reduce the thickness of the edge D) All of the above |
C) Reduce the thickness of the edge
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What are required minimum instruments used to check rigid lenses when they are received from the laboratory?
A) Lensometer B) Thickness gauge C) Diameter gauge or reticle D) Radiuscope E) All of the above |
E) All of the above
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Why do moderate to high myopes usually make good contact lens patients?
A) Image size is larger B) Motivation is usually high among myopes C) Better peripheral vision D) All of the above |
D) All of the above
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What would be a disadvantage to a hydrophilic contact lens?
A) More initial sensation likely B) More corneal changes likely C) Fluorescein cannot be used to evaluate the lens D) All of the above |
C) Fluorescein cannot be used to evaluate the lens
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Dynamic fluorescein pattern is observed:
A) When the patient is staring with his eyes in a straight ahead position B) Right after the patient has blinked C) When the lens has returned to its normal position D) None of the above |
B) Right after the patient has blinked
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Poor vision after contact lenses have been removed and replaced with spectacle lenses is called:
A) Blurring B) Foggy C) Spectacle blur D) Contact lens blur |
C) Spectacle blur
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Which of the following instruments is used to measure the optical zone of a contact lens?
A) Measuring magnifier B) Radiuscope C) Contactometer D) Conversion Table |
A) Measuring magnifier
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Development of new blood vessels in the cornea is called:
A) Neovascularization B) Avascular C) Transparency D) Keratopathy |
A) Neovascularization
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Which of the following modifications cannot be performed on a rigid gas permeable contact lens?
A) Blend transition B) Flatten secondary curve C) Reduce optical zone diameter D) Steepen peripheral curves |
D) Steepen peripheral curves
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When changing the power of a rigid lens, the following may be added with the most ease:
A) Plus power B) Minus power C) Cylinder power D) Prism |
B) Minus power
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A posterior intermediate curve is ground on a contact lens to:
A) Reduce the diameter B) Tighten the fit C) Loosen the lens D) Taper the edge |
C) Loosen the lens
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The patient complains that his eyes feel "hot" after four hours of wear. This indicates a:
A) Loose lens B) Tight lens C) Large lens D) Small lens E) None of the above |
B) Tight lens
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All of the following are functions of a wetting solution except:
A) It converts the hydrophobic lens surface to a hydrophilic one B) It provides a viscous protective coating over the lens surface so the lens does not come in direct contact with the finger during insertion C) It provides lubrication between the lid and lens surface D) It cleans the lenses after their removal from the eye |
D) It cleans the lenses after their removal from the eye
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All of the following are functions of a soaking (disinfected) solution except:
A) It aids in cleaning the lens of ocular secretions after it is removed B) It prevents eye infections by a contaminated lens C) It permits the lens to float freely D) It maintains a state of hydrated equilibrium |
A) It aids in cleaning the lens of ocular secretions after it is removed
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When correcting low hyperopes with presbyopia, they might best be managed with the following lens design:
A) Bifocal lenses B) Bitoric lenses C) Prism ballast lenses D) Lenses for distance only |
D) Lenses for distance only
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Scleral impression is generally the result of:
A) Poor fitting rigid lenses B) Poor fitting upper lid attachment lenses C) Loose fitting soft lenses D) Tight fitting soft lenses |
D) Tight fitting soft lenses
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Three and nine o'clock staining is generally seen with:
A) Rigid lenses B) Soft lenses C) Gas permeable lenses D) Both a and c are correct |
D) Both a and c are correct
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If a rigid contact lens causes slight stagnation of tears over the apex of the cornea, the preferred modification would be:
A) Reduced lens diameter B) Widen peripheral curve C) Widen lenticulation D) Reduce optical zone |
B) Widen peripheral curve
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The best lens to manage K:42.00/42.50; Rx -2.00-0.50x90 would be:
A) Toric lens B) Spherical rigid lens C) Spherical soft lens D) Toric soft lens |
C) Spherical soft lens
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Neovascularization observed in contact lens patient should cause the fitter to:
A) Photograph B) Change the fit C) Use a different material D) Return the patient to the referring practitioner |
D) Return the patient to the referring practitioner
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What should the power for the following patient's contact lens be if it is fitted 0.50D steeper than the flat K? Rx: -3.50+0.50x90
A) -3.50 B) -3.25 C) -3.75 D) None of the above |
A) -3.50
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Reducing the diameter of a minus lens results in:
A) An increased center thickness B) A steeper centeral posterior curve C) A decreased center thickness D) A reduction in weight |
D) A reduction in weight
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The advantage of a minus carrier contact lens in fitting aphakic wearers is that it:
A) Is more comfortable B) Centers better C) Is easier to insert D) Is easier to keep clean |
B) Centers better
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Which of the following is the most accurate for measuring lens diameter?
A) Millimeter rule B) Measuring magnifier C)Radiuscope D) Lensometer |
B) Measuring magnifier
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It is important to consider vertex distance when the prescription is greater than plus or minus:
A) 2.00 D B) 3.00 D C) 4.00 D D) 7.00 D |
C) 4.00
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When Bausch and Lomb Soflenses are being compared, the O series are:
A) Thinner B) Smaller C) Larger D) Thicker |
A) Thinner
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Which of the following most likely indicates a front toric lens?
A) K:41.00 @180/ 41.25 @90 Rx: -1.00-0.25x90 B) K:41.00 @175/ 42.25 @85 Rx: -3.00-1.00x05 C) K:41.00 @180/ 41.00 @90 Rx: -1.00-4.00x180 D) K: 44.50 @168 / 45.62 @78 Rx: -3.75-0.75x175 |
C) K:41.00 @180/ 41.00 @90 Rx: -1.00-4.00x180
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Which of the following is NOT considered to be a normal adaptive symptom?
A) Slight injection of the sclera B) Tearing C) Lens falling out frequently D) Excessive blinking |
C) Lens falling out frequently
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If a patient's prescription is -2.50+0.25x90 and the lens is to be fitted 0.75 diopters steeper then the flattest meridian of the cornea, the power of the contact lens should be:
A) -3.25 B) -3.00 C) -2.75 D) -2.00 |
B) -3.00
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Which of the following need not be recorded on each follow-up visit?
A) Keratometry and topography B) Lens changes and modifications C) Original Rx and lens specifications D) Subjective and objective findings |
C) Original Rx and lens specifications
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A successful wearer of soft contact lenses for 6 months presents a sudden onset of varying visual acuity, lens decentration, and decreased comfort. The most likely cause is:
A) Too flat a fit B) The wrong diameter C) Lens inversion D) Too steep fit |
C) Lens inversion
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At the time of delivery, a patient complains that the lens of the right eye feels scratchy, that vision is intermittent, and there is mild tearing and scleral injection. What should the fitter do first?
A) Check the edge design B) Perform keratometry C) Redesign the lens D) Reduce the lens diameter |
A) Check the edge design
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Which of the following is the most commonly used for detecting corneal edema?
A) Sclerotic scatter and the naked eye B) Focal illumination C) Cobalt light D) Penlight |
A) Sclerotic scatter and the naked eye
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If slit lamp evaluation reveals a corneal abrasion the fitter should:
A) Stop contact lens wear for one week and recheck B) Stop contact lens wear and send the patient to the prescribing practitioner C) Reduce wearing time by one half, and reschedule the patient in one week D) Reduce wearing time by one half, and reschedule the patient in one month |
B) Stop contact lens wear and send the patient to the prescribing practitioner
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41.87 @90/ 43.62 @180. This K reading indicates:
A) Astigmatism against the rule B) Astigmatism with the rule C) Oblique astigmatism D) Hyperopia |
A) Astigmatism against the rule
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A patient reports hazy vision with haloes after removing the contact lens. Which of the following would most likely be the problem?
A) Corneal edema B) Presbyopia C) Residual astigmatism D) Improper contact lens power |
A) Corneal edema
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The power and thickness of the lacrimal lens will vary with the:
A) Lens-cornea relationship B) Lens thickness C) "K" reading D) Refraction |
A) Lens-cornea relationship
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When a lathe-cut soft lens is being fitted, it is determined that the fit is slightly tight. The CPC of the current lens is 8.20mm. Which base curve should be used next?
A) 7.80 B) 8.00 C) 8.40 D) 9.40 |
C) 8.40
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When lenses are delivered to the patient, the wearing schedule should be:
A) Determined by patient's comfort level B) Unspecified C) Verbal and written D) Determined by refraction |
C) Verbal and written
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If a patient's refraction over a spherical powered corneal lens indicates residual astigmatism, the patient's acuity can best be corrected with a:
A) Darker tinted lens B) Spherical lens based on the spherical equivalent C) Cylinder lens D) Small thin lens |
C) Cylinder lens
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All of the following are functions of the precorneal film:
A) Providing carbon dioxide B) Acting as a lubricant to the cornea C) Furnishing a smooth optical surface for the cornea D) Supplying nutrition to the cornea |
A) Providing carbon dioxide
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The fitting characteristics of a rigid gas permeable lens can be altered by:
A) Changing the CPC B) Polishing the front surface C) Reducing the diameter D) Cleaning the lens E) Both a and c are correct |
E) Both a and c are correct
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The edge of a contact lens is mostly inspected with a:
A) Hand magnifier B) Radiuscope C) Lensometer D) Keratometer |
A) Hand magnifier
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