ABO Practice Test ACTUAL UPDATED QUESTIONS AND
CORRECT ANSWERS
When discussing thick lenses, the factors which are d. front curve, back curve, thickness and index
considered in computing the lens power are:
a. front curve, thickness and index
b. back curve, thickness and index
c. front curve, back curve and thickness
d. front curve, back curve, thickness and index
Toric transposition shows: b. power in principal meridians
a. lens thickness
b. power in principal meridians
c. the power of the ADD
d. the lens diameter
Increasing the diameter of a minus power lens always c. weight
increases its:
a. vertex power
b. center thickness
c. weight
d. refractive index
,The optical center of a round segment is located: b. in the geometric center of the segment
a. at the very top of the segment
b. in the geometric center of the segment
c. 5 mm from the top of the segment
d. at the very bottom of the segment
The base curve of any multifocal lens is found on the c. segment
surface containing the:
a. cross curve
b. cylinder surface
c. segment
d. ocular curve
Normal slab-off (bicentric grind) is ground on the lens c. least plus power
whose vertical meridian has the:
a. strongest curves
b. most plus power
c. least plus power
d. least minus power
The refractive error indicated by the Rx +1.75 -2.75 x 090 d. mixed astigmatism
is:
a. compound hyperopic astigmatism
b. compound myopic astigmatism
c. simple myopic astigmatism
d. mixed astigmatism
Tempering a lens by heat treating results in a lens being: b. more resistant to impact
a. less resistant to impact
b. more resistant to impact
c. more resistant to surface scratching
d. impossible to break
A slab-off lens is for the correction of: c. excessive prism imbalance at the reading level
a. astigmatic errors
b. excessive weight of lens
c. excessive prism imbalance at the reading level
d. exotropia
Chem-tempering makes a glass lens more impact a. ion exchange
resistant by placing the lens in a potassium nitrate bath.
The lens undergoes a process known as:
a. ion exchange
b. iron oxide activation
c. silver halide transfer
d. thermal bleaching
, Which wavelengths of light have been indicated as c. 350-400 nm
possible contributors to the onset of cataracts?
a. 400-520 nm
b. 520-635 nm
c. 350-400 nm
d. 635-750 nm
When the lenses are laid out and marked for cutting and a. to avoid unwanted prism
edging, the lenses are usually decentered so as to
correspond to the patient's pupillary distance after lenses
are inserted. This is done for the following reason:
a. to avoid unwanted prism
b. for cosmetic effect
c. to use off-center lenses
d. to avoid thick edges on the nasal side
Light falling on the front surface of a spectacle lens is: a. partially reflected, partially absorbed and the remainder refracted
a. partially reflected, partially absorbed and the
remainder refracted
b. partially reflected and the remainder refracted
c. partially absorbed and the remainder refracted
d. totally refracted
A concave mirror: a. can focus parallel incident rays to form a real image
a. can focus parallel incident rays to form a real image
b. can focus parallel incident rays to form a virtual image
c. always produces inverted images of real objects
d. produces virtual images smaller than the real object
White light is broken into its component colors when it is: d. diffracted or refracted
a. diffracted
b. refracted
c. reflected
d. diffracted or refracted
To the viewer; the image seen in a plane mirror appears d. as far behind the mirror as the object is in front of it
to be:
a. inverted
b. one-half as large as the object
c. twice as large as the object
d. as far behind the mirror as the object is in front of it
CORRECT ANSWERS
When discussing thick lenses, the factors which are d. front curve, back curve, thickness and index
considered in computing the lens power are:
a. front curve, thickness and index
b. back curve, thickness and index
c. front curve, back curve and thickness
d. front curve, back curve, thickness and index
Toric transposition shows: b. power in principal meridians
a. lens thickness
b. power in principal meridians
c. the power of the ADD
d. the lens diameter
Increasing the diameter of a minus power lens always c. weight
increases its:
a. vertex power
b. center thickness
c. weight
d. refractive index
,The optical center of a round segment is located: b. in the geometric center of the segment
a. at the very top of the segment
b. in the geometric center of the segment
c. 5 mm from the top of the segment
d. at the very bottom of the segment
The base curve of any multifocal lens is found on the c. segment
surface containing the:
a. cross curve
b. cylinder surface
c. segment
d. ocular curve
Normal slab-off (bicentric grind) is ground on the lens c. least plus power
whose vertical meridian has the:
a. strongest curves
b. most plus power
c. least plus power
d. least minus power
The refractive error indicated by the Rx +1.75 -2.75 x 090 d. mixed astigmatism
is:
a. compound hyperopic astigmatism
b. compound myopic astigmatism
c. simple myopic astigmatism
d. mixed astigmatism
Tempering a lens by heat treating results in a lens being: b. more resistant to impact
a. less resistant to impact
b. more resistant to impact
c. more resistant to surface scratching
d. impossible to break
A slab-off lens is for the correction of: c. excessive prism imbalance at the reading level
a. astigmatic errors
b. excessive weight of lens
c. excessive prism imbalance at the reading level
d. exotropia
Chem-tempering makes a glass lens more impact a. ion exchange
resistant by placing the lens in a potassium nitrate bath.
The lens undergoes a process known as:
a. ion exchange
b. iron oxide activation
c. silver halide transfer
d. thermal bleaching
, Which wavelengths of light have been indicated as c. 350-400 nm
possible contributors to the onset of cataracts?
a. 400-520 nm
b. 520-635 nm
c. 350-400 nm
d. 635-750 nm
When the lenses are laid out and marked for cutting and a. to avoid unwanted prism
edging, the lenses are usually decentered so as to
correspond to the patient's pupillary distance after lenses
are inserted. This is done for the following reason:
a. to avoid unwanted prism
b. for cosmetic effect
c. to use off-center lenses
d. to avoid thick edges on the nasal side
Light falling on the front surface of a spectacle lens is: a. partially reflected, partially absorbed and the remainder refracted
a. partially reflected, partially absorbed and the
remainder refracted
b. partially reflected and the remainder refracted
c. partially absorbed and the remainder refracted
d. totally refracted
A concave mirror: a. can focus parallel incident rays to form a real image
a. can focus parallel incident rays to form a real image
b. can focus parallel incident rays to form a virtual image
c. always produces inverted images of real objects
d. produces virtual images smaller than the real object
White light is broken into its component colors when it is: d. diffracted or refracted
a. diffracted
b. refracted
c. reflected
d. diffracted or refracted
To the viewer; the image seen in a plane mirror appears d. as far behind the mirror as the object is in front of it
to be:
a. inverted
b. one-half as large as the object
c. twice as large as the object
d. as far behind the mirror as the object is in front of it
