CONTACT LENS (HARD&SOFT) (1.0) Flashcards
- The cornea is thinnest
A. Upon awakening B. One hour after awakening C. During sleep D. Just prior to sleep E. One hour prior to awakening
D. Just prior to sleep
- The water content of a hydrocurve lens is approximately
A. 30%
B. 45%
C. 54%
D. 21%
C. 54%
- In general, the soft lens is recommended when the
A. Spherical ametropia is between +20 to -20 D
B. Refractive astigmatism is less than 3.00 D
C. Corneal radius is between 39.00
and 49.00
D. Corneal toricity is 2.00 D or less
Both A and D are correct
A. Spherical ametropia is between +20 to -20 D
D. Corneal toricity is 2.00 D or less
- Which of the following conditions (disorders) prevents hard contact lens wear?
A. Diabetes
B. Allergy
C. Color blindness
D. Asthma
Both A and D are correct
A. Diabetes
D. Asthma
- Which of the following statements concerning Image size with contact lenses is correct?
A. The retinal image size is smaller for a myope corrected with contact lenses instead of spectacles
B. The retinal image size is greater for a myope corrected with contact lenses instead of spectacles
C. The retinal image size is greater for a hyperope corrected
with contact lenses instead of spectacles
B. The retinal image size is greater for a myope corrected with contact lenses instead of spectacles
- Which of the following eye conditions will not prevent hard contact lens wear?
A. Trichiasis B. Blepharitis C. Meibomianitis D. Chalazion E. Hordeolum
A. Trichiasis
- Silicone lenses are highly permeable to
A. Oxygen
B. Carbon dioxide
A and B
A. Oxygen
B. Carbon dioxide
- Regarding diurnal variation in central corneal curvature, is found that the cornea is
A. Flattest in the morning
B. Steepest in the early evening
A and B
A. Flattest in the morning
B. Steepest in the early evening
- The plus series soft lens has a front surface radius of
A. 6.2 mm
B. 6.7 mm
C. 7.2 mm
D. 7.7 mm
B. 6.7 mm
- The hydrogel lens has little or no therapeutic application in which of the following pathological processes?
A. Bullous keratopathy B. Keratitis sicca C. Recurrent corneal ulcers D. Epithelial erosion E. Keratoconus
E. Keratoconus
- When compared to hard contact lenses, the hydrogel lens offers the distinct advantage of
A. Stabilized visual acuity
B. Durability
C. Reduced adaptation time
D. Minimal spectacle blur
Both C and D
C. Reduced adaptation time
D. Minimal spectacle blur
- Which of the following factors are enhanced with contact lenses in myopia?
A. Convergence B. Accommodation C. Usable field D. Aberrations E. Image size
Both C and E are correct
C. Usable field
E. Image size
- It is generally accepted that a hard contact lens with a posterior toric surface should be recommended when the corneal
astigmatism is
A. 0.00 D 0.50 D
B. 0.50 D 1.00 D
C. 1.00 D 2.00 D
D. 2.00 D or more
D. 2.00 D or more
- Prism ballasted anterior toric hard contact lenses are recommended to correct for internal residual astigmatism when the corneal astigmatism is below
A. 4.00 D
B. 3.00 D
C. 2.00 D
D. 1.00 D
C. 2.00 D
- The normal corneal thickness is approximately
A. 0.32 mm B. 0.42 mm C. 0.52 mm D. 0.62 mm E. 0.72 mm
C. 0.52 mm
- The F series soft lens has a
A. Diameter of 13.5 mm B. Anterior radius of 8.2 mm C. Thickness of 0.9 mm D. Power range from -0.25 to -6.00 E. None of the above
D. Power range from -0.25 to -6.00
- What method can be used to correct for internal residual astigmatism/greater than 1.00 D when corneal hard contact lenses are used?
A. Toric base curve with an anterior spherical surface
B. Spherical central, anterior, and posterior surfaces
C. Spherical base curve and anterior toric surface
Both A and B are correct
A. Toric base curve with an anterior spherical surface
B. Spherical central, anterior, and posterior surfaces
- The proper procedure required to read the power of a soft lens is to
A. Read the power off the bottle
B. Put the lens directly from the bottle onto the vertometer and take a power reading
C. Dry the lens, wait 10 seconds, and read the power on the lensometer
D. Read the power off the alpascope
C. Dry the lens, wait 10 seconds, and read the power on the lensometer
- Which of the following statements concerning and convergence accommodation through contact lenses is correct?
A. A myope requires less accommodative convergence when corrected by contact lenses
B. A myope requires more accommodative convergence when corrected by spectacle lenses
C. A myope requires more accommodative convergence when corrected with contact lenses
B. A myope requires more accommodative convergence when corrected by spectacle lenses
- The Hydro Curve Contact Lens is made of a material with a refractive index of
A. 1.52 B. 1.49 C. 1.43 D. 1.39 E. 1.33
C. 1.43
- When internal residual astigmatism exists only in one eye and is corrected with a prism ballast lens, the other eye must be corrected with the same ballast. Otherwise,
A. The difference in chromatic aberration is annoying
B. Aniseikonia is induced
C. A vertical phoria is induced
D. A horizontal phoria is induced
C. A vertical phoria is induced
- Which of the following must accommodate more with contact lenses than with spectacle lenses?
A. Hyperopes
B. Emmetropes
C. Myopes
D. Aphakics
C. Myopes
- Which of the following six early symptoms require a change in the hard contact lens?
A. Adaptive problems B. Procedural error by patient C. Psychological problems of patient D. Fitting error E. None of the above
D. Fitting error
- The flattest series of the B & L Soflens series is
A. B
B. F
C. J
D. N
A. B
