Prefitting
Contact lenses are most often specified in:
A. Back vertex power
B. Sphero-cylinder power
C. Power in situ
D. Posterior apical radius
A. Back vertex power
A patient is fit with a -3.00 diagnostic lens. An over-refraction shows the need for an additional -0.50 -0.50 x 90. What lens power should be ordered?
A. -3.00
B. -3.50
C. -3.75
D. -4.00
C. -3.75
The preservative in contact lens solutions:
A. Must demonstrate efficacy in killing bacterial, viral, and fungal microorganisms
B. Must kill all microorganisms in a 4 hour soak period
C. Is usually a mercury compound such as thimerosal
D. Is formulated to keep microorganisms from multiplying in a contact lens solution bottle after it has been opened
D. Is formulated to keep microorganisms from multiplying in a contact lens solution bottle after it has been opened
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
Which one of the following prescriptions indicates against-the-rule astigmatism?
A. –4.50 +1.00 x075
B. –4.50 +1.00 x180
C. –4.50 –1.00 x165
D. –4.50 –1.00 x180
B. –4.50 +1.00 x180
The part of a contact lens that contains thepower of a contact lens?
A. Central posterior curve
B. Optic zone
C. Central anterior curve
D. Diameter
B. Optic zone
Which instrument do we use to assess three point touch?
A soft toric lens that is thick across the belly and thinned out at the top and bottom is called:
A. Dynamic stabilization
B. Prism ballast
C. Bitoric
D. Truncated lens
A. Dynamic stabilization
Staining at the inferior portion of the cornea of a soft lens wearer is usually caused by:
A. A loose lens
B. A tight lens
C. Improper lens removal
D. A lens that is too large
C. Improper lens removal
The Dk value of a lens is:
A. The way the lens wets
B. Oxygen permeability
C. Oxygen transmissibility
D. The resultant sagittal value of the posterior curves
B. Oxygen permeability
Contact lenses are classified by the FDA bywhich two components?
A. Water content and electrostatic properties
B. Water content and thickness
C. Water content and Dk value
D. Water content and material
A. Water content and electrostatic properties
The base curve a GP lens is best checked using a:
A. Keratometer
B. Radiuscope
C. Measuring Magnifier
D. Radius dial gauge
B. Radiuscope
The oxidation method of disinfecting soft lenses uses
A. heat
B. hydrogen peroxide
C. chlorehexidine
D. subtilisin
B. hydrogen peroxide
The most useful slit lamp illumination to view neovascularization:
A. Parallelpiped
B. Indirect illumination
C. Sclerotic scatter
D. Diffuse illumination
B. Indirect illumination
To use the slit lamp with retroillumination, the light beam is bounced or reflected off the:
A. ciliary body.
B. macula.
C. cornea.
D. iris.
D. iris
Fitting soft lenses steeper than K will usually result in:
A. Good lens movement
B. A minus tear layer under the lens
C. Fluctuations in vision following the blink
D. Good apical contact
C. Fluctuations in vision following the blink
Which type of cells will be visible with fluorescein stain?
Damaged epithelial cells
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
An in-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
A contact lens wearer presents for follow-up while taking an over-the-counter decongestant/ antihistamine. Which ocular change would you most likely expect?
A. Edema of the puncta
B. Increased lacrimation
C. Increased thickness of the crystalline lens
D. Corneal dehydration
D. Corneal dehydration
Which lens designs would provide the best visual result for this patient?
K's 43.00 @ 180/42.50 @ 90
Rx: -3.50 -1.75 x 180
Spherical soft, spherical GP, soft toric, or BST?
Soft toric lens
Daily Double:
During three point touch, you notice the mires are blurry before the blink, clear immediately after the blink, but then are blurry again. This would indicate the lens is fitting:
Too tight
If a soft 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
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
C. Irrigate the eye with saline or rewetting drops until the lens begins to move freely again
Which of the following should be suspected when there are large fluctuations in a patient's refractive error?
A. Diabetes
B. Graves' disease
C. Rhinitis
D. Sjogren's syndrome
A. Diabetes
Which of the following disinfecting agents is recommended for a soft contact lens patient with a history of allergic reactions?
A. Benzalkonium chloride
B. Hydrogen peroxide
C. Chlorhexidine
D. Thimerosal
B. Hydrogen peroxide