NCLE practice test
the F.D.A. tests solutions for the effective microorganism kill ratio for _____ major groups of eye pathogens. a. 4 b. 6 c. 8 d. 10
a. 4
which of the following is an abnormal tear break up time? a. 5 sec b. 15 sec c. 20 sec d. 30 sec
a. 5 sec
Which magnification would be appropriate for performing a general survey of the eye at the beginning of a slit lamp examination? a. 6x b. 15x c. 25x d. 40x
a. 6x
a soft lens with a visibility tint absorbs how much light? a. <10% b. 10-20% c. 40-60% d. >90%
a. <10%
which of the following polishes should NOT be used to polish gas permeable lenses? a. Silvo b. Sil-O2-Care c. Alox d. X-Pal
a. Silvo
during over-refraction, the term "fogging" refers to: a. adding plus power to relax accommodation b. adding minus power to stimulate accommodation c. chilling the lens before insertion d. adding prism to break fusion
a. adding plus power to relax accommodation
a spin cast lens will generate: a. an aspheric back surface b. a spherical back surface c. a topic back surface d. all of the above
a. an aspheric back surface
_____________________ is a moderate to high refractive difference in the powers of the two eyes a. anisometropia b. myopia c. aberration d. hyperopia
a. anisometropia
The most powerful refracting surface of the human eye is the___________________ a. anterior cornea b. posterior cornea c. anterior lens d. posterior lens
a. anterior cornea
the anterior cornea's main source of oxygen is the: a. atmosphere b. short posterior ciliary arteries c. aqueous humor d. central retinal vein
a. atmosphere
When myopic patients view an object at near through their spectacles, the prism created through the spectacles is _________________________ a. base in b. base out c. neutral d. oblique
a. base in
another name for the slit lamp is the: a. biomicroscope b. phoropter c. optic spherometer d. radius gauge
a. biomicroscope
after the sharp junctures between curves on the lens posterior are smoothed out, they are called: a. blends b. bevels c. lenticulation d. apex
a. blends
the most common method of removal of rigid lenses is the "------" method. a. blink b. roll c. pinch d. dig
a. blink
when diffuse illumination is used in conjunction with fluorescein, what filter should be employed? a. blue (UV light) b. red-free (green light) c. diffuse d. no filter (white light)
a. blue (UV light)
the apical diameter of the cornea: a. can be measured by topograpical keratometry b. cannot be measured by topographical keratometry c. is unimportant d. is smaller than the keratometer mire in all eyes
a. can be measured by topographical keratometry
the initial follow-up check for extended wear patients should be scheduled _____ day(s) after lens delivery. a. 1 b. 3 c. 7 d. 14
a. 1
an arc stain seen on the cornea under the peripheral or intermediate portion of a contact lens means that: 1. bevels are too sharp 2. lens needs to be blended 3. base curve is too flat 4. lens is too large a. 1 and 2 b. 1 and 3 c. 2 and 3 d. 3 and 4
a. 1 and 2
the index of refraction used to calibrate the keratometer is: a. 1.3375 b. 4.215 c. 1.49 d. 1.51
a. 1.3375
patients with a tear break-up time of less than _____ seconds should NOT be considered for extended wear. a. 10 b. 20 c. 30 d. 40
a. 10
the keratometer derives its measurement of a meridian from how many points on the cornea? a. 2 b. 4 c. 6 d. 8
a. 2
when explaining care procedures to patients, they hear about _____% of what you say. a. 25 b. 50 c. 75 d. 85
a. 25
all the colors we perceive are produced by the ___________ different photopigments found in retinal cones a. 3 b. 36 c. 64 d. 140
a. 3
which of the following best describes the lens/cornea relationship of a properly fit soft lens? a. 3-point touch b. corneal slignment c. apical clearance d. scleral blanching
a. 3-point touch
the scale on the topogometer shows the number of millimeters the eye has moved from the: a. optical axis of the instrument b. mire c. visual iris d. visual center of the cornea
a. optical axis of the instrument
the chemical make-up of a hydrogel lens material is listed in the: a. package insert b. fitting guide c. consumer advertisements d. patient instructions
a. package insert
which of the following is NOT necessary for a successful soft lens fit? a. perfect centration b. three point touch c. adequate movement d. patient comfort
a. perfect centration
ingredients added to contact lens solutions to protect them from spoilage after being opened are called: a. preservatives b. disinfectants c. chelating agents d. buffering agents
a. preservatives
which design feature is useful for rotation control of a front topic contact lens? a. prism ballast b. small diameter c. seg height d. thick edge lenticular
a. prism ballast
the main function of the eye's outer layer is: a. protection b. nutrition c. illumination d. light sensation
a. protection
which instrument can be used to detect warpage of a rigid contact lens? a. radiuscope b. lensometer c. topogometer d. measuring magnifier
a. radiuscope
which instrument is LEAST likely to be used for in-office verification of soft lenses? a . radiuscope b. lensmeter c. slit lamp d. measuring magnifier
a. radiuscope
the levator superioris muscle: a. raises the upper lid b. creates intorsion c. raises the eyeball d. coordinates both eyes
a. raises the upper lid
for patients with a moderate amount of corneal astigmatism (between 1 and 2 diopters), which lens type will provide the crispest, most stable vision? a. rigid spherical b. soft spherical c. rigid toric d. soft toric
a. rigid spherical
Which of the following conditions is a contraindication to contact lens wear? a. severe blepharitis b. keratoconus c. bullous keratopathy d. irregular astigmatism
a. severe blepharitis
a normal tear break-up time is: a. less than 5 seconds b. 10-12 seconds c. 6-7 seconds d. over 60 seconds
b. 10-12 seconds
the normal blink rate is approximately ______________ times per minute a. 6 b. 12 c. 24 d. 48
b. 12
the historical development of the slit lamp dates back to: a. 1801 b. 1891 c. 1931 d. 1951
b. 1891
which of the following adverse effects is related to extended wearing of rigid lenses more than soft lenses? a. edema b. 3 & 9 o'clock stain c. neovascularization d. suface deposits
b. 3 & 9 o'clock stain
the range of curvatures the keratometer can measure without auxiliary lenses is: a. 26.00 D to 50.00 D b. 36.00 D to 52.00 D c. 40.00 D to 42.00 D d. 45.00 D to 60.00 D
b. 36.00 D to 52.00 D
studies have shown that as high as ______% of compliant contact lens patients have contact lens cases that culture positive. a. 15 b. 42 c. 52 d. 75
b. 42
a patient wearing a 43.00D base curve, 9.0mm diameter, 7.0mm optical zone diameter requires a change to a 9.5mm diameter with a 7.5mm optical zone diameter. To keep the base curve corneal bearing relationship the same, the new base curve would need to be: a. 42.50D b. 42.75D c. 43.50D d. 43.75D
b. 42.75D
during most illumination procedures, the beam and the microscope will from an angle of: a. 25 degrees b. 45 degress c. 60 degress d. 90 degrees
b. 45 degrees
loss of vision caused by excessive intraocular pressure is called: a. presbyopia b. glaucoma c. trachoma d. keratitis
b. glaucoma
the oxidation method of disinfecting soft lenses uses: a. heat b. hydrogen peroxide c. chlorhexidine d. subtilisin
b. hydrogen peroxide
which of the following conditions is MOST suitable to soft lens wear? a. marginal dry eye b. intermittent wear c. dusty environment d. irregular corneal astigmatism
b. intermittent wear
Mounting the lens blank in the lathe so that the face of the button is perpendicular to the spindle is necessary to avoid: a. heat build-up b. unwanted prism c. cylinder power d. warpage
b. unwanted prism
the term that describes the amount of curvature of a light wave is: a. power b. vergence c. focus d. index
b. vergence
the lens aberration that results in fringes of color around images is: a. spherical aberration b. marginal astigmatism c. chromatic aberration d. distortion
c. chromatic aberration
the goblet cells that secrete mucous into the tear film are located in which structure? a. ciliary body b. retina c. conjunctiva d. tarsal plate of the eyelid
c. conjunctiva
inflammation of the mucous membrane that lines the inside of the eyelids and covers the anterior globe except for the cornea is called: a. anridia b. blepharitis c. conjunctivitis d. dacryocystitis
c. conjunctivitis
corneal measurement by keratometry is based on the principles of image formation by a __________________________ a. plane mirror b. concave mirror c. convex mirror d. reflecting prism
c. convex mirror
Spectacle blur is caused by: a. dirty glasses b. wearing sunglasses indoors c. corneal changes d. glasses worn over contacts
c. corneal changes
tear break up time (BUT) is verified with what slit lamp illumination? a. indirect b. direct c. diffuse d. retro
c. diffuse
in the making of concentric style bifocals, the different power zones (distance and near) may be ground on: a. the front surface b. the back surface c. either surface d. both surfaces
c. either surface
the corneal layer that consists of a single layer of hexagonal cells is the: a. epithelium b. bowman's membrane c. endothelium d. stroma
c. endothelium
another name for the duochrome test is the ______test. a. red/blue b. black/white c. yellow/green d. red/green
d. red/green
the keratometer is patented and trademarked by: a. omega b. danker c. american optical d. reichert
d. reichert
over-refracting patients wearing rigid contact lenses usually reveals little, if any: a. spherical equivalent b. tears c. staining d. residual cylinder
d. residual cylinder
the preferred method of vision correction in keratoconus is: a. spectacles b. surgery c. soft contact lenses d. rigid contact lenses
d. rigid contact lenses
the most useful slit lamp illumination to view gross corneal edema from rigid lens wear is: a. retro b. indirect c. direct d. sclerotic scatter
d. sclerotic scatter
which of the following will cause flare? a. allergies b. spoiled solution c. wrong power d. small optical zone
d. small optical zone
_________ may cause blurred vision due to its direct action on accommodation a. rheumatoid arthritis b. thyroid disease c. respiratory allergies d. endocrine changes e. lanoxin f. donnatal g. acutane
f. donnatal
when taking follow-up K readings to compare with the original K's, how much change is acceptable? a. 0.50D b. 1.00D c. 1.50D d. 2.00D
a. 0.50D
an Rx of -2.00 -1.50 x 180 and K reading of 43.00 @180/46.00 @90 would have a calculated residual astigmatism of: a. +1.50 x180 b. +2.00 x90 c. +1.50 x90 d. +1.00 x180
a. +1.50 x180
Spectacle Rx +6.00 +4.00 x 90, K's 43.50 @ 180 / 47.37 @ 90, VD = 13 mm. If a rigid lens with a PCC of 7.85/7.36 is fit, what lens power should be ordered? a. +12.00 -4.00 x 180 b. +12.00 -5.00 x 180 c. +11.50 - 4.00 x 180 d. +11.50 -5.00 x 180
a. +12.00 -4.00 x 180
the vergence of a wave at a point in a pencil of rays is +6.00 D. what will the vergence be at a point 3 cm to the right? a. +5.08 b. +6.00 c. +7.32 d. +8.15
a. +5.08
a patient fit 0.50D flatter than K with a contact lens power of -1.00D would most likely have a spherical component of ______ in their spectacle Rx, when in minus cylinder form. a. -0.50D b. -1.50D c. -2.00D d. none of the above
a. -0.50D
a lens with a focal length of -40 cm has a power of ____________ D a. -2.50 b. +2.50 c. -4.00 d. +4.00
a. -2.50
the ideal finished edge thickness for rigid lenses, regardless of whether they are plus or minus, is _____ mm a. 0.08-0.12 b. 0.04-0.10 c. 0.20-0.44 d. 0.5-1.0
a. 0.08-0.12
most systemic medications taken by patients are of concern to fitters because they: a. cause changes in the tear film b. make patients forgetful c. create fluctuations in vision d. a and b
a. cause changes in the tear film
calculation of which lens parameter is NOT under the control of the fitter: a. central posterior curve b. posterior optical zone c. anterior power curve d. center thickness
a. central posterior curve
corneal microcysts are caused by: a. chronic hypoxia b. flat fitting lenses c. non-preserved solutions d. a and b
a. chronic hypoxia
the tear lens formed behind a rigid contact lens corrects which type of astigmatism? a. corneal b. lenticular c. refractive d. residual
a. corneal
the eyepiece of the keratometer should be focused: a. daily b. every other day c. weekly d. monthly
a. daily
which type of cells will be visible with fluorescein stain? a. damaged epitelial b. striated c. enlarged endothelial d. aqueous
a. damaged epithelial
staining at 3 & 9 o'clock found on a patient with no history of staining at previous follow-ups may signal: a. deposits b. lens binding c. poor keratometry d. Rx change
a. deposits
the unit of measurement used for vergence is the: a. diopter b. meter c. nanometer d. joule
a. diopter
under slit lamp evaluation with fluorescein, corneal areas that appear dark and do not hold stain during blinks are most likely: a. dry spots b. verrucae c. punctates d. infiltrates
a. dry spots
in aspheric lens design, the change in curvature that occurs from the center to the edge of the aspheric zone is called: a. eccentricity b. equilibration c. effectivity d. enormosity
a. eccentricity
cloudy vision upon awakening is indicative of: a. edema b. 3 & 9 o'clock stain c. corneal infiltrates d. vertical striae
a. edema
the most serious long term risk to extended wear patients may be from: a. endothelial changes b. conjunctivitis c. ulcerative keratitis d. melanoma
a. endothelial changes
which layer of the cornea makes up 10% of the structure's total thickness? a. epithelium b. bowman's membrane c. endothelium d. stroma
a. epithelium
a rigid lens showing apical touch indicates a: a. flat fit b. steep fit c. large fit d. small fit
a. flat fit
as light waves travel away from a source, the become gradually... a. flatter b. steeper c. faster d. slower
a. flatter
which of the following lens designs would most likely be used for correction of residual astigmatism? a. front toric b. back toric c. bitoric d. bifocal
a. front toric
which type of lens is used to correct residual astigmatism? a. front toric b. multifocal c. hydrophilic d. aspheric
a. front toric
if a rigid lens decanters off of the cornea: a. gently massage the lens back to center through the lids b. gently place a fingernail under the lens and pop it off c. place a finger directly on the lens and slide it back on d. all of the above
a. gently massage the lens back to center through the lids
which of the following is an indication for extended wear? a. history of patient compliance b. history of pollen allergies c. superman syndrome d. diabetes
a. history of patient compliance
when using original K readings to refit a former PMMA wearer with gas permeable lenses, it is best to refit: a. immediately b. after seven days of no contact lens wear c. after one month of no contact lens wear d. none of the above
a. immediately
staining at the inferior portion of the cornea of a soft lens wearer is usually caused by: a. improper lens removal b. a loose lens c. a tight lens d. a lens that is too large
a. improper lens removal
after dispensing extended wear lenses, the initial follow-up check should be performed: a. in the early morning b. during lunch hour c. in the late afternoon d. whenever there is an opening
a. in the early morning
which of the following is the most likely cause of 3 and 9 o'clock staining? a. inadequate blinking b. base curve too flat c. Dk of lens material too low d. base curve too steep
a. inadequate blinking
which of the following instruments is most beneficial in verifying three point touch? a. keratometer b. lensmeter c. slit lamp d. pachometer
a. keratometer
on the first follow-up visit, a patient cannot see as well as they did one week earlier upon delivery of the lenses. Which of the following is the LEAST likely cause? a. lenses are the wrong power b. lenses are inverted c. lenses are soiled d. lenses are switched
a. lenses are the wrong power
the bacteriocidal ingredient found in the precorneal tear film is: a. lysozyme b. papain c. sodium chloride d. lactic acid
a. lysozyme
straight wetting solutions are used to: a. make rigid lens surfaces hydrophilic b. make rigid lens surfaces hydrophobic c. disinfect rigid lenses d. A and C
a. make rigid lens surfaces hydrophilic
a _____________________ person must accommodate more when viewing near objects through their contact lenses vs. spectacles a. myopic b. hyperopic c. astigmatism d. presbyopic
a. myopic
when reading the radius of curvature of the back surface with the radiuscope, the lens is floated on a drop of liquid to: a. neutralize the reflection from the front surface b. keep the front surface clean c. level the lens d. none of the above
a. neutralize the reflection from the front surface
the middle layer of the three main layers of the globe is mostly responsible for: a. nutrition b. light sensitivity c. protection d. ocular motility
a. nutrition
the fovea centralis of the retina contains: a. only cones b. both cones and rods c. only rods d. neither cones or rods
a. only cones
which slit lamp illumination is performed with the microscope placed precisely along the angle of reflected light from the eye? a. specular reflection b. sclerotic scatter c. optic section d. diffuse
a. specular reflection
blurring of images due to a greater amount of refraction toward the lens edge is called: a. spherical aberration b. marginal astigmatism c. chromatic aberration d. distortion
a. spherical aberration
a patient with an upper lid that does not cover any portion of the superior portion of the cornea would be best fit: a. steeper than K with a small diameter b. flatter than K with a large diameter c. on K with an 8.8 mm diameter d. none of the above
a. steeper than K with a small diameter
disposable lenses minimize problems caused by: a. surface deposits b. a tight fit c. hypoxia d. loose fitting lenses
a. surface deposits
giant papillary conjunctivitis (GPC) in soft lens wearers is associated with: a. surface deposits b. small lenses c. loose lenses d. lack of disinfection
a. surface deposits
gently vending a soft lens to make sure it is not inside out before insertion is called the ______ test. a. taco b. fajita c. chimichanga d. burrito
a. taco
when the light is reflected by any surface, which statement is true? a. the angle of reflection equals the angle of incidence b. the angle of reflection > the angle of incidence c. the angle of reflection < the angle of incidence d. the angle of incidence exceeds the critical angle
a. the angle of reflection equals the angle of incidence
a contact lens technician uses the slit lamp to view all of the following except: a. the fundus b. corneal scars c. corneal neovascularization d. the conjunctiva
a. the fundus
When the keratometer is out of focus on the cornea: a. the lower right mire is doubled b. a repair man should be called c. have the patient move forward or back d. this is an unimportant finding
a. the lower right mire is doubled
when light is incident on a glass/air boundary at an angle exceeding the critical angle, the result is: a. total internal reflection b. refraction c. minimum deviation d. dispersion
a. total internal reflection
Thimerosal is: a. used in concentrations of from 1:5,000 to 1:100,000 b. a mild preservative with a low patient sensitivity ratio c. very effective against gram-negative organisms d. all of the above
a. used in concentrations of from 1:5,000 to 1:100,000
a spherical RGP lens fit on K shows fluorescein pooling under the superior and inferior portions of contact lens, and a dark band of minimal fluorescein horizontally. What kind of astigmatism does this pattern represent? a. with-the-rule b. against-the-rule c. residual d. oblique
a. with-the-rule
two thin lenses are in contact. the first has a focal length of +12.5 cm. and the second has a focal length of -33 cm. What is the total power of the system? a. -3.00 D b. +5.00 D c. -11.00 D d. +20.50 D
b. +5.00 D
a patient refracted at a vertex distance of 13 mm has a spectacle Rx 0f -3.00 +2.00 x 070 and K's of 42.50 @ 160 / 44.50 @ 70. A rigid lens with a back surface radius of 7.94mm is placed on the eye. the expected power of the contact lens needed would be what? a. -0.50 b. -1.00 c. -3.00 d. -1.00 -2.00 x 160
b. -1.00
a light wave that has traveled 50 cm from a point source will have a vergence of _____________________ D a. +2.00 b. -2.00 c. +5.00 d. -5.00
b. -2.00
in-office power changes should be limited to +/- _________D. or less. a. 0.25 b. 0.50 c. 1.00 d. 2.00
b. 0.50
the vertical measurement of the palpebral fissure for an average eye is ____________________ mm a. 5 b. 10 c. 15 d. 20
b. 10
a diagnostic lens with a base curve of 7.67mm and an optical zone diameter of 7.6mm fits too tight. Which of the following changes will lessen the fit the most? a. 7.76mm, 8.0mm b. 7.69mm, 7.8mm c. 7.63mm, 7.6mm d. 7.71mm, 7.3mm
b. 7.69mm, 78mm
a certain brand of soft lens is available in base curves of 8.0, 8.3, and 8.6mm, and a diameter of 14.0mm. Which base curve should be selected first for evaluation on a patient with small, steep eyes? a. 8.0 b. 8.3 c. 8.6 d. any of these
b. 8.3
a -10.00D. Rx for a spectacle correction would most likely need a contact lens with a power of: a. -8.00D b. -9.25D c. -10.50D d. -11.75D
b. 9.25D
the term GMP is the acronym for: a. Government Mandated Processes b. Good Manufacturing Practices c. Graded Member Projections d. Granted Marketing Procedures
b. Good Manufacturing Practices
most bandage lenses are made of: a. PMMA b. HEMA c. glass d. liquid crystal
b. HEMA
when the reichert keratometer is properly aligned in front of an eye, the patient will see: a. the operator's eye b. a green light c. the eye occluder d. the horizontal measuring drum
b. a green light
a patient with an Rx of +2.00 -1.00 x90 and K readings of 44.00 @180/43.00 @ 90 reveals residual astigmatism of plano -2.00 x 180. A possible explanation for this is: a. normal residual astigmatism b. a steeply fitted contact lens c. a warped contact lens d. none of the above
b. a steeply fitted contact lens
the "taco test" is: a. an F.D.A. test for antimicrobial effectiveness b. a way to tell if a soft lens is inverted c. a way to tell if patients understand their care system d. none of the above
b. a way to tell if a soft lens is inverted
Rays of light striking a spectacle lens at its edge create ____________ or distortion. a. oblique b. aberration c. astigmatism d. cylinder
b. aberration
patients should clean lenses with a surfactant cleaner: a. before insertion b. after removal c. on a weekly basis d. whenever they feel dirty
b. after removal
K readings of 47.12 @ 180 / 45.50 @ 90 indicate which type of corneal astigmatism? a. with-the-rule b. against-the-rule c. oblique d. irregular
b. against-the-rule
the spherical equivalent correction is: a. half the sphere power plus all cylinder power b. all sphere power plus half the cylinder power c. all sphere power plus twice the cylinder power d. half the sphere power plus half the cylinder power
b. all sphere power plus half the cylinder power
When part of the mire is reflected from the transitional zone: a. an accurate reading is taken b. an inaccurate reading is taken c. no reading is possible d. the mire image will be too small
b. an inaccurate reading is taken
the lensmeter is designed to measure the __________________________ of contact lenses and spectacle lenses a. front vertex power b. back vertex power c. equivalent power d. thin lens power
b. back vertex power
which of the following in NOT an advantage of rigid gas permeable lenses over soft lenses? a. longer lens life b. better initial comfort c. better optical quality d. fewer adverse effects
b. better initial comfort
the limiting margin of the apex: a. cannot be found by topographical keratometry b. can be found by topographical keratometry c. is unimportant d. does not exist
b. can be found by topographical keratometry
when rigid lenses are manufactured, which parameter is cut first? a. anterior convex curve b. central posterior curve c. CN bevel d. posterior peripheral curve
b. central posterior curve
the apical clearance fitting philosophy requires a lens that positions: a. centrally, with upper lid attachment b. centrally and intrapalpebrally c. superiorly, with upper lid attachment d. superiorly and intrapalpebrally
b. centrally and intrapalpebrally
In addition to measuring the cornea, the keratometer can be used to: a. check the power of a contact lens b. check the curvature of a contact lens c. check the thickness of a contact lens d. check the diameter of a contact lens
b. check the curvature of a contact lens
the most refractive optical component of the eye is the: a. retina b. cornea c. ciliary body d. crystalline lens
b. cornea
epithelial thinning is a result of: a. stromal swelling b. decreased cell mitosis c. polymegathism d. increased oxygenation
b. decreased cell mitosis
which two lens parameters determine the sagittal depth of the lens? a. base curve, power b. diameter, base curve c. power, thickness d. thickness, diameter
b. diameter, base curve
the slit lamp illumination that gives an overall assessment of the contact lens fit, but no fine detail, is: a. direct b. diffuse c. retro d. sclerotic scatter
b. diffuse
agents that destroy, neutralize, or inhibit growth of pathogenic organisms on contact lenses are called: a. preservatives b. disinfectants c. chelating agents d. buffering agents
b. disinfectants
the separation of white light into its spectral components is called: a. scattering b. dispersion c. reflection d. vergence
b. dispersion
which of the following conditions is LEAST suitable to soft lens wear? a. wide palpebral fissure b. dusty environment c. moderate corneal astigmatism d. dry environment
b. dusty environment
when decompression of the _________________ occurs, aqueous humor leaks into the anterior layers of the cornea forming bullae a. stroma b. endothelium c. epithelium d. conjunctiva
b. endothelium
the doubling device of the keratometer is necessary due to: a. poor fixation of the eye b. fine tremor of the eye c. vertex distance d. the transitional zone of the cornea
b. fine tremor of the eye
which of the following reasons for failure with daily wear lenses may be remedied by switching to extended wear? a. chronic edema b. frequent lens damage c. surface deposits d. lens dryness
b. frequent lens damage
the amount of corneal astigmatism: a. cannot be measured with the keratometer b. is the difference between the reading on the horizontal and vertical drums c. is calculated by multiplying the axis times the horizontal drum reading d. is calculated by multiplying the axis times the vertical drum reading
b. is the difference between the reading on the horizontal and vertical drums
which of the following is experienced by most soft lens wearers? a. poor vision b. lens dryness c. neovascularization d. superficial punctate keratitis
b. lens dryness
the transitional area that joins the cornea and the sclera is known as the: a. fundus b. limbus c. aqueous d. strabismus
b. limbus
excessive tilting of a lens will cause: a. spherical aberration b. marginal astigmatism c. chromatic aberration d. distortion
b. marginal astigmatism
the two main parts of the biomicroscope are the _________________ and the ________________ a. microscope, chin rest b. microscope, light source c. eyepiece, power drum d. light source, joy stick
b. microscope, light source
Objects in the field of vision of a high myope are ___when spectacles are worn. a) magnified b) minified c) oblique d) irregular
b. minified
new blood vessels appearing in the corneal tissue is called: a. angioplasty b. neovascularization c. keratitis d. phlebitis
b. neovascularitzation
polishing the surface of rigid gas permeable lenses should be performed: a. every six months b. only when it is needed c. every year d. never
b. only when it is needed
the eyelid muscle responsible for closure of the lids is the: a. dilator pupillae b. orbicularis oculi c. levator superioris d. pectoral blephari
b. orbicularis oculi
Fitting a rigid contact lens steeper than the flattest corneal meridian will introduce power into the lacrimal lens. a) minus sphere b) plus sphere c) minus cylinder d) plus cylinder
b. plus sphere
a rigid contact lens material used widely in the 1950s, '60s, and '70s was: a. silicone acrylate b. polymethylmethacrylate c. cellulose acetate butyrate d. none of the above
b. polymethylmethacrylate
when performing prefitting keratometry, which of the following observations may indicate poor tear quality? a. high dioptric readings b. poor quality mires c. oblique axis d. all of the above
b. poor quality mires
the best way to begin a training session is by explaining: a. insertion and removal b. proper use of solutions c. adaptive symptoms d. abnormal symptoms
b. proper use of solutions
corneal exposure to 3% hydrogen peroxide causes: a. epithelial basement membrane defects b. punctate epithelial staining c. mild stinging due to low pH d. A and C
b. punctate epithelial staining
which of the following instruments would NOT be used to verify the lens diameter in the office? a. diameter gauge b. radiuscope c. measuring magnifier d. projection magnifier
b. radiuscope
the additive primary colors are: a. red, white, blue b. red, green, blue c. red, yellow, blue d. orange, green, blue
b. red, green, blue
oily deposit on lens surfaces, from soap or other cosmetics, causes: a. smoother surfaces for lids to glide over b. reduced wettability c. lens warpage d. jelly bumps
b. reduced wettability
the main difference between conventional extended wear lenses and disposable lenses is in the: a. material composition b. replacement schedule c. reproducibility d. tint
b. replacement schedule
what slit lamp illumination is preferred for viewing corneal microcysts? a. indirect b. retro c. sclerotic scatter d. optic section
b. retro
Which slit lamp illumination can be used without the aid of the microscope? a. specular reflection b. sclerotic scatter c. diffuse d. retro
b. sclerotic scatter
parallel rays of light striking an optical system will converge toward (or diverge away from) a common point called the _________________: a. first principal focus b. second principal focus c. front vertex b. back vertex
b. second principal focus
a rigid lens showing apical pooling indicates a: a. flat fit b. steep fit c. large fit d. small fit
b. steep fit
to achieve apical clearance with a rigid gas permeable lens of 8.5mm diameter, fit on a cornea of average size, the base curve should be: a. on K b. steeper than K c. flatter than K d. none of the above
b. steeper than K
when a spherical rigid contact lens is placed on an eye that has corneal cylinder, the resulting lacrimal lens will have cylinder power on: a. the anterior surface b. the posterior surface c. both surfaces d. neither surface
b. the posterior surface
through spectacles, the astigmatic patient with "against-the-rule" astigmatism will view a square as follows: a. the square will appear slightly longer in the horizontal meridian b. the square will appear slightly elongated in the vertical meridian c. the square will appear slightly tilted d. there will be no difference in the appearance of the square
b. the square will appear slightly elongated in the vertical meridian
_________ predisposes the eye to drying due to proptosis a. rheumatoid arthritis b. thyroid disease c. respiratory allergies d. endocrine changes e. lanoxin f. donnatal g. acutane
b. thyroid disease
removal of plastic from the bottom of a lens to produce a flat edge that will control rotation is called: a. prism ballast b. truncation c. base curve d. blending
b. truncation
optical infinity is considered to be _________________ feet a. ten b. twenty c. forty d. one hundred
b. twenty
if present, spectacle blur should disappear how long after lens removal? a. thirty seconds b. twenty minutes c. sixty minutes d. three hours
b. twenty minutes
a patient with an Rx of +3.00 +0.50 x90 fit 0.50D flatter than K would require a power of: a. +3.00D b. +3.50D c. +4.00D d. none of the above
c. +4.00D
spectacle Rx +4.12 +0.75 x90, K's 44.50 @180/44.87 @90, VD=13mm. What power soft lens would be expected to give the best correction? a. +4.00 b. +4.25 c. +4.50 d. +4.75
c. +4.50
A patient fit with a base curve of 43.00D and a power of -3.00D and then refit with a base curve of 43.50D would require a new power of: a. -2.50D b. -2.75D c. -3.50D d. -4.00D
c. -3.50D
a patient is fit with a -3.00 rigid diagnostic lens. Over refraction shows the need for an additional -0.50 -0.50 x 90. What lens power should be ordered? how did you get this answer? a. -3.00 b. -3.50 c. -3.75 d. -4.00
c. -3.75 add overrefraction to og power, then spherical equivalent
a patient with a base curve of 42.75D, power of -3.00D, if refit with a lens of base curve of 43.50D, would then require a power of: a. -2.50D b. -3.50D c.-3.75D d. none of the above
c. -3.75D
rigid gas permeable lens edge thickness should be between ______mm and _____mm. a. 002-0.05 b. 0.05-0.10 c. 0.08-0.12 d. 0.10-0.30
c. 0.08-0.12
In the latter stages of keratoconus, the following may be observed 1. munson's sign 2. distorted mires 3. corneal opacities 4. fleischer's ring a. 1 only b. 1 and 3 c. 1, 2, 3, and 4 d. none are correct
c. 1, 2, 3, and 4
a ray of light in air is incident upon a plane glass surface at an angle of 40 degrees. If the angle of refraction is 22 degrees, what is the index of refraction of the glass? a. 1.50 b. 1.58 c. 1.72 d. 1.80
c. 1.72
the average reading distance for most patients is ______ inches. a. 10 to 12 b. 12 to 14 c. 14 to 16 d. 16 to 18
c. 14 to 16
the speed of light in a vacuum is ___________________ mi/sec a. 153,000 b. 168,000 c. 186,000 d. 242,000
c. 186,000
the recommended time for allowing soft lenses to equilibrate on the eye before evaluation isa at least ______ minutes. a. 3 b. 10 c. 20 d. 45
c. 20
the chord length of the mire measured by the keratometer without auxiliary lenses is: a. 3.8 mm to 1.4 mm b. 2.8 mm to 1.8 mm c. 3.8 mm to 2.6 mm d. 4.8 mm to 3.2 mm
c. 3.8 mm to 2.6 mm
the far point for a 3.00 D myope is approximately _________________ in front of the eye a. 1 m b. 50 cm c. 33 cm d. 16.7 cm
c. 33 cm
the maximum time recommended for continuous wear before removal for cleaning and disinfection is: a. 24 hours b. 3 days c. 7 days d. 30 days
c. 7 days
saline solutions should be buffered to a pH of approximately: a. 3.4 b. 5.4 c. 7.4 d. 8.4
c. 7.4
the distance from the front of the keratometer to the front of the cornea when the instrument is in focus is: a. 40.0 mm b. 64.0 mm c. 75.0 mm d. 32.0 mm
c. 75.0 mm
most soft lenses should fit with ______ movement upon blinking? a. no b. < 1mm c. > 1mm d. at lease 2mm
c. > 1mm
an ins-office modification that can be done to thin the edge of a minus lens is the: a. hyperflange b. myoflange c. CN bevel d. ski edge
c. CN bevel
when a rigid lens in place, a fluorescein pattern shows a narrow band of dark vertically, and pooling horizontally. this is indicative of: a. a spherical base curve on a spherical cornea b. a spherical base curve on a with-the-rule toric cornea c. a spherical base curve on a against-the-rule toric cornea d. a toric base curve on a toric cornea
c. a spherical base curve on a against-the-rule toric cornea
the follow-up exam with lenses in situ should b conducted: a. immediately after insertion b. before lenses are inserted c. after six hours of wear d. upon awakening
c. after six hours of wear
Subtilisin is: a. a multi-purpose disinfectant b. a gram-negative rod c. an enzyme d. none of the above
c. an enzyme
a lens fit with a base curve steeper than the flattest K with a diameter of 8.5mm would follow which fitting philosphy? a. cornmeal alignment b. 3-point touch c. apical clearance d. none of the above
c. apical clearance
Spectacle Rx +6.00 +4.00 x 90, K's 43.50 @ 180 / 47.37 @ 90, VD = 13 mm. which of the following rigid lens designs bet describes the lens ordered? a. spherical b. front toric c. back toric d. bitoric
c. back toric
__________________________ lenses are used on patients with recurrent epithelial erosions a. toric b. scleral c. bandage d. lenticular
c. bandage
quality of lens surfaces should be evaluated by the fitter: a. while on the eye b. while off of the eye c. both on and off the eye d. if the patient complains
c. both on and off the eye
which of the following soft lens parameters CANNOT be specified by the contact lens technician: a. power b. diameter c. center thickness d. base curve
c. center thickness
a back toric rigid contact lens fit on K to conform to each corneal meridian will show a fluorescein pattern that is: a. concentrated under the center of the lens b. concentrated under the edge of the lens c. evenly distributed d. vertically oriented
c. evenly distributed
the topogometer allows the eye to: a. fixate on an image of the eye b. fixate on the apex c. fixate on a moveable light d. fixate on an immovable light
c. fixate on a moveable light
which of the following patients will experience the most image magnification? a. myope wearing spectacles b. myope wearing contacts c. hyperope wearing spectacles d. hyperope wearing contacts
c. hyperope wearing spectacles
Errors in keratometry occur: a) very seldom b) in 75% of readings c) in keratoconus and irregular astigmatism d) in reading ball bearings
c. in keratoconus and irregular astigmatism
which of the following is a contraindication to the fitting of bandage lenses? a. neovascularization b. bullous keratopathy c. inability to follow-up d. diabetes
c. inability to follow-up
The green filter is used in conjunction with which slit lamp illumination a. specular reflection b. conical beam c. indirect d. optic section
c. indirect
the practitioner should suspect ______________________________ astigmatism if there is a difference between the amount of cylinder found by keratometry readings and the amount of cylinder found by refractometry a. corneal b. oblique c. internal d. myopic
c. internal
the axis of corneal astigmatism when taking a K reading: a. is unimportant b. is the last thing to align c. is the first thing to align d. cannot be found on high degrees of astigmatism
c. is the first thing to align
______________________ is a developmental anomaly of the cornea that results in irregular myopic astigmatism a. emmetropia b. nystagmus c. keratoconus d. aniridia
c. keratoconus
the anterior ciliary arteries terminate at the: a. optic nerve b. choroid c. limbus d. iris
c. limbus
pupillary constriction is called: a. cycloplegia b. esophoria c. miosis d. ocular motility
c. miosis
when the spectacle Rx must be compensated for a contact lens worn at the corneal plane, the contact lens power will always be _____________________________ a. stronger b. weaker c. more plus d. more minus
c. more plus
a myope wearing contact lenses will have to converge __________________________ and accommodate ______________________ when viewing near objects, as compared to viewing the same near objects through spectacles. a. less, less b. more, less c. more, more d. less, more
c. more, more
soft lenses should be inserted: a. directly on the cornea b. in the inferior cul-de-sac c. on the inferior sclera d. on the medial canthus
c. on the inferior sclera
thicker lenses perform better in all of the following categories EXCEPT: a. lens dryness b. handling c. oxygen permeability d. visual acuity
c. oxygen permeability
when a rigid lens is fit on K the sphere power of the lacrimal lens is _________________________ a. plus b. minus c. plano d. half of the cylinder
c. plano
steeper curvatures than normally readable with the keratometer can be taken by adding what to the front of the instrument? a. plus (+) 10.00 trial lenses b. minus (-) 10.00 trial lenses c. plus (+) 1.25 trial lenses d. minus (-) 1.00 trial lenses
c. plus (+) 1.25 trial lenses
the lens stabilization system most often used to prevent or control rotation of topic soft lenses is: a. lenticularization b. truncation c. prism ballast d. thin zones (double slab off)
c. prism ballast
if movement is not readily apparent when evaluating the fit of bandage lenses, the fitter should: a. not fit the patient with bandage lenses b. instill lubricating drops and evaluate again c. push the lens up with the lower lid d. check movement with the retinoscope
c. push the lens up with the lower lid
an abnormal symptom of contact lens wear is: a. a mild foreign body sensation b. itching c. redness of the eye that doesn't clear up d. none of the above
c. redness of the eye that doesn't clear up
__________ usually causes photophobia, itching, lacrimation and burning a. rheumatoid arthritis b. thyroid disease c. respiratory allergies d. endocrine changes e. lanoxin f. donnatal g. acutane
c. respiratory allergies
which of the following is NOT a good reason for patients wanting extended wear lenses? a. long work hours b. frequent traveler c. save money on solutions d. erratic work schedule
c. save money on solutions
the slit lamp illumination where a narrow beam of light bisects the corneo-scleral juncture is: a. oscillatory b. indirect retro c. sclerotic scatter d. transverse axial
c. sclerotic scatter
how many extrinsic muscles are attached to each eye? a. two b. four c. six d. eight
c. six
which is NOT a catalyst used in hydrogen peroxide systems? a. sodium pyruvate b. sodium sulfate c. sodium carbonate d. sodium thiosulfate
c. sodium carbonate
during the lathing process for topic lenses, cylinder power is generated by: a. using a cylindrical diamond cutting tool b. blocking the lens off center c. squeezing the lens in a crimping tool d. truncating the lens
c. squeezing the lens in a crimping tool
the condition where one eye is turned is called: a. rubeosis b. neovascularization c. strabismus d. orthophoria
c. strabismus
which of the following structures would belong to the adnexa oculi? a. ciliary muscle b. optic disc c. tarsal plate d. lens zonule
c. tarsal plate
When a rigid contact lens is worn, corneal astigmatism is neutralized by: a. spectacles b. the contact lens c. the lacrimal lens d. the crystalline lens
c. the lacrimal lens
When classic keratometry is performed by having the patient sight on the mirrored image of their eye, alignment of what is accomplished? a. the apex with the visual axis b. the optical axis with the apex c. the optical axis with the visual axis d. the posterior axis with the primary axis
c. the optical axis with the visual axis
patients who have hypesthetic corneas are not good candidates for bandage lenses because: a. the lenses always cause discomfort b. the lenses interfere with the healing process c. they do not feel the discomfort that signals a problem d. they soil lenses more rapidly
c. they do not feel the discomfort that signals a problem
hydrogel lens materials allow the transport of oxygen to the cornea and carbon dioxide away from the cornea because they contain: a. acrylic polymer chains b. water bound to reactive sites c. three dimensional polymers d. none of the above
c. three dimensional polymers
the recommended lens/cornea relationship when fitting soft lenses is: a. corneal alignment b. mean of the mean c. three point touch d. apical clearance
c. three point touch
a patient with a corneal toxicity of 4.50 diopters would be best suited with a base curve that is: a. 1.00 diopter steeper than K b. 1.50 diopter steeper than K c. toric d. none of the above
c. toric
The image of an object viewed through a prism will be displaced: a. up b. down c. toward the apex d. toward the base
c. toward the apex
the most serious immediate risk to wearers of extended wear lenses is from: a. endothelial changes b. conjunctivitis c. ulcerative keratitis d. melanoma
c. ulcerative keratitis
which of the following terms is associated with the corneal alignment fitting philosophy? a. central pooling b. intrapalpebral fit c. upper lid attachment d. 3 point touch
c. upper lid attachment
the term used to describe both eyes moving in the same direction, as when they both look left or both look right, is: a. vergence b. vitreous c. version d. virgule
c. version
the FDA has created four lens groups to clarify categories of similar hydrophilic lens polymers. These groups are defined by: a. method of manufacture b. diameter and thickness of the lens c. water content and electrostatic properties d. none of the above
c. water content and electrostatic properties
a hydrophobic lens surface: a. is water loving b. allows tears to spread evenly over its surface c. will fog up d. A and B
c. will fog up
the popularity of soft lenses can largely be attributed to which of the following characteristics? a. initial comfort b. low cost c. ease of care d. all of these
d. all of these
the axial length of the human eye is about: a. 0.5 cm b. 0.5 in c. 1 cm d. 1 in
d. 1 in
conventional extended wear soft lenses should be replaced at a maximum age of: a. 2 weeks b. 3 months c. 6 months d. 1 year
d. 1 year
K readings of 41.37 @ 05 / 42.87 @ 95 indicate how much corneal cylinder? a. none b. 0.37 c. 0.87 d. 1.50
d. 1.50
What is the prismatic effect 4mm from the optical center of a +5.00 lens a. 0.50 /\ b. 1.00 /\ c. 1.50 /\ d. 2.00 /\
d. 2.00 /\
the diameter of soft lens should be at least _______ the corneal diameter. a. 1mm smaller than b. 1mm larger than c. the same as d. 2mm larger than
d. 2mm larger than
Through strong aphakic spectacles, a patient will see an object ________________ larger compared to the normal image size. a) 7% b) 10% c) 15% d) 33%
d. 33%
the size of the mire (target) on the front of the keratometer is: a. 40 mm b. 32.6 mm c. 337.0 mm d. 64.0 mm
d. 64.0 mm
a typical optical zone diameter of a corneal alignment fit would be: a. 6.5mm b. 7.0mm c. 7.5mm d. 8.0mm
d. 8.0mm
patients who mix solutions may: a. experience irritation b. discolor their lenses c. raise the pH of their lenses d. A and B
d. A and B
an advantage to heat disinfection is that: a. it is inexpensive b. it can be used on lenses of 55% water content c. it can be used for patients with solution sensitivities d. A and C
d. A and C
Polyquad is: a. a substitute for papain b. a low concentration antimicrobial agent c. used as a disinfectant in some multi-purpose solutions d. B and C
d. B and C
in relation to contact lens follow-up examinations, the acronym SOAP stands for: a. Solutions Offer Answers to Problems b. Service Only After Payment c. Spectacles Off All Patients d. Subjective Objective Assessment Plan
d. Subjective Objective Assessment Plan
bandage lenses are used in cases of bullous keratopathy for: a. reducing pain b. speeding evaporation of corneal fluid c. enhancing corneal hydration d. a and b
d. a and b
When fitting rigid lenses, residual astigmatism is most often caused by: a) high refractive cylinder b) a toric contact lens c) corneal cylinder against-the-rule d) a difference between refractive and corneal cylinder
d. a difference between refractive and corneal cylinder
disposable soft lenses avoid most problems cause by: a. surface deposits b. surface dryness c. allergies d. adaptation
d. adaptation
which in-office modification is the easiest to perform? a. changing base curve b. adding plus power c. truncation d. adding minus power
d. adding minus power
after reducing the overall diameter, which of the following additional modifications are required? a. applying peripheral curves b. blending c. edge shaping and polishing d. all of the above
d. all of the above
an adaptive symptom of contact lens wear is: a. a mild foreign body sensation b. itching c. dryness d. all of the above
d. all of the above
buttons and raw materials used in hydrogel lens manufacturing are tested and quarantined: a. to ensure that they comply with approved standards b. to ensure that they meet approved specifications c. before they can be used in production d. all of the above
d. all of the above
during the lathe cutting process, humidity must be controlled at a low level in order to: a. avoid premature hydration b. maintain quality standards c. avoid distraction of the lens d. all of the above
d. all of the above
surface deposits on lenses may: a. decrease comfort b. cause GPC c. reduce permeability d. all of the above
d. all of the above
the slit lamp is used in evaluation of which fitting characteristics of soft contact lenses? a. centration b. movement c. corneal coverage d. all of the above
d. all of the above
therapeutic lenses may serve which of the following functions? a. pain relief b. corneal protection c. visual improvement d. all of the above
d. all of the above
to improve patient compliance, you should: a. give patients written instructions b. have patients watch a biofilm c. review care at the yearly visit if needed d. all of the above
d. all of the above
when adverse corneal changes are observed, the fitter should: a. notify the prescribing doctor b. adjust the lens parameters accordingly c. switch to non-preserved solutions d. all of the above
d. all of the above
when watching patients demonstrate proper use of their care system, you should be sure that: a. they don't touch the tips of the solutions bottles b. they clean the lenses using a back-and-forth motion c. they understand the function of each solution d. all of the above
d. all of the above
which of the following may be responsible for decreased visual acuity? a. edema b. surface deposits c. Rx change d. all of the above
d. all of the above
contact lens problems may be related to: a. using the wrong solutions b. a dirty case c. patient non-compliance d. all of these
d. all of these
long term success with extended wear lenses is dependent upon: a. frequent follow-up visits b. power cleaning and disinfection c. good lens movement d. all of these
d. all of these
The bony orbit of the eye is shaped most like a: a. ball b. cube c. trapezoid d. pyramid
d. pyramid
upon delivery of soft lenses, fitters should provide patients with ______ regarding insertion, removal, and care procedures. a. verbal instructions b. demonstrations c. witten instructions d. all of these
d. all of these
When the lens power is verified, placing the concave surface against the lensmeter aperture will reveal power. a. effective b. front vertex c. true d. back vertex
d. back vertex
Rx -1.00 -4.25 x 180, K's 41.75 @ 180 / 45.75 @ 090. Which rigid lens design would most likely be needed? a. spherical b. front toric c. back toric d. bitoric
d. bitoric
which of the following parameters of hydrogel lenses can be readily verified in the office? a. base curve b. power c. diameter d. both ab and c
d. both b and c
an opacity of the crystalline lens is referred to as a: a. melanoma b. pinguecula c. presbyopia d. cataract
d. cataract
aqueous humor is secreted by the: a. meibomian glands b. cones and rods c. cornea d. ciliary body
d. ciliary body
patients who want to try a different care regimen should: a. try whatever is on sale b. use what their friends use c. keep using what their fitter gave them, even if they are unhappy d. consult with their fitter about possible alternatives
d. consult with their fitter about possible alternatives
the structure that can adjust its focus for various object positions is the: a. cornea b. retina c. vitreous humor d. crystalline lens
d. crystalline lens
the slit lamp illumination that shows the entire contact lens, movement, and centration is: a. retro b. direct c. indirect d. diffuse
d. diffuse
the reflection of the keratometer mire is measured in: a. hundredths of millimeters b. thousandths of inches c. isopters d. diopters
d. diopters
central corneal clouding is a sign of: a. polymegathism b. corneal flattening c. cell mitosis d. edema
d. edema
swelling of the corneal tissue, or any tissue, is called: a. blepharitis b. dystrophy c. cataract d. edema
d. edema
which RGP parameter is critical for proper tear exchange? a. thickness b. diameter c. anterior optical zone d. edge lift
d. edge lift
________ causes changes in the fluid balance of the body a. rheumatoid arthritis b. thyroid disease c. respiratory allergies d. endocrine changes e. lanoxin f. donnatal g. acutane
d. endocrine changes
polymegathism, or variation in cell size, is a possible adverse effect of contact lens wear located in which layer of the cornea? a. epithelium b. Bowman's membrane c. stroma d. endothelium
d. endothelium
the keratometer eyepiece if not properly focused can cause: a. distortion of the mire b. a cylinder to be induced c. the image of the mire to disappear d. errors in correctly reading curvature
d. errors in correctly reading curvature
a rigid lens which flexes upon the eye would be best corrected by going: a. steeper b. steeper and thicker c. flatter d. flatter and thicker
d. flatter and thicker
it is advisable to always fit the _____ soft lens that meets all fitting criteria. a. strongest b. weakest c. steepest d. flattest
d. flattest
the point at which light rays converge is called a: a. object b. image c. source d. focus
d. focus
the transition zone between the bulbar conjunctiva and the palpebral conjunctiva is called the: a. fundus b. blend c. limbus d. fornix
d. fornix
what color is fluorescein when viewed under ultraviolet light? a. red b. blue c. orange d. green
d. green
what filter is used to improve detection of corneal vascularity? a. white b. yellow c. blue d. green
d. green
________________________ ___________________________ results when the cornea has been damaged by trauma, inflammation or scar tissue a. hyperopic astigmatism b. myopic astigmatism c. emmetropic astigmatism d. irregular astigmatism
d. irregular astigmatism
the visual error caused by a cylindrical crystalline lens is known as _____________________________ astigmatism a. corneal b. oblique c. myopic d. lenticular
d. lenticular
a dense opacity of the cornea is called a: a. dendrite b. nebula c. fovea d. leukoma
d. leukoma
during the subjective examination, you should: a. ignore everything patients complain about, because they do not know what is important b. only listen to complaints and criticism c. only listen to positive statements d. listen to everything, and select the useful information
d. listen to everything, and select the useful information
lens blends and "ski edge" can be verified using a: a. keratometer b. junctometer c. radiuscope d. long fluorescent light bulb
d. long fluorescent light bulb
any ophthalmic lens moved closer to the eye becomes effectively: a. flatter b. steeper c. more plus d. more minus
d. more minus
a properly fit spherical soft lens will form a lacrimal lens that has _________________________ power a. sphere b. cylinder c. both sphere and cylinder d. neither sphere nor cylinder
d. neither sphere nor cylinder
When an optic section is used in conjunction with fluorescein, what filter should be employed? a. blue (UV) b. red free (green) c. diffuse d. no filter (white)
d. no filter (white)
the optical zone diameter of a rigid contact lens is generally: a. 3.0mm smaller than the total diameter b. 3.5mm smaller than the total diameter c. 4.2mm smaller than the total diameter d. none of the above
d. none of the above
which of the following hydrogel lens parameters may be modified in the practitioner's office? a. base curve b. power c. diameter d. none of the above
d. none of the above
when measuring the horizontal meridian with the keratometer: a. the minus mires are superimposed b. the black central focusing cross hair should be in the left hand circle c. the plus mires will be in the vertical meridian d. the plus mires are superimposed
d. the plus mires are superimposed
if the whole mire is reflected from the apex: a. the reading is accurate b. the reading is undependable c. no reading is possible d. the reading will be too flat
d. the reading will be too flat
convex mirrors form images that are always _______________________ a. real, erect, and smaller b. virtual, erect, and larger c. virtual, inverted, and larger d. virtual, erect, and smaller
d. virtual, erect, and smaller
the addition of fluorine to the rigid lens ingredients increases: a. durability b. permeability c. optical quality d. wettability
d. wettability
what color filter enhances the fluorescein pattern behind a rigid lens containing a UV blocker? a. grey b. green c. red d. yellow
d. yellow
_________ is a systemic drug used in the treatment of acne a. rheumatoid arthritis b. thyroid disease c. respiratory allergies d. endocrine changes e. lanoxin f. donnatal g. acutane
g. acutane