ABO PRACTICE EXAMINATION TEST 2026
COMPLETE QUESTIONS AND ANSWERS
GRADED A+
◉ Toric transposition shows:
a. lens thickness
b. power in principal meridians
c. the power of the ADD
d. the lens diameter. Answer: b. power in principal meridians
◉ Increasing the diameter of a minus power lens always increases
its:
a. vertex power
b. center thickness
c. weight
d. refractive index. Answer: c. weight
◉ The optical center of a round segment is located:
,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. Answer: b. in the geometric
center of the segment
◉ The base curve of any multifocal lens is found on the surface
containing the:
a. cross curve
b. cylinder surface
c. segment
d. ocular curve. Answer: c. segment
◉ Normal slab-off (bicentric grind) is ground on the lens whose
vertical meridian has the:
a. strongest curves
b. most plus power
c. least plus power
d. least minus power. Answer: c. least plus power
,◉ The refractive error indicated by the Rx +1.75 -2.75 x 090 is:
a. compound hyperopic astigmatism
b. compound myopic astigmatism
c. simple myopic astigmatism
d. mixed astigmatism. Answer: d. mixed astigmatism
◉ Tempering a lens by heat treating results in a lens being:
a. less resistant to impact
b. more resistant to impact
c. more resistant to surface scratching
d. impossible to break. Answer: b. more resistant to impact
◉ A slab-off lens is for the correction of:
a. astigmatic errors
b. excessive weight of lens
c. excessive prism imbalance at the reading level
d. exotropia. Answer: c. excessive prism imbalance at the reading
level
, ◉ Chem-tempering makes a glass lens more impact 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. Answer: a. ion exchange
◉ Which wavelengths of light have been indicated as possible
contributors to the onset of cataracts?
a. 400-520 nm
b. 520-635 nm
c. 350-400 nm
d. 635-750 nm. Answer: c. 350-400 nm
◉ When the lenses are laid out and marked for cutting and 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
COMPLETE QUESTIONS AND ANSWERS
GRADED A+
◉ Toric transposition shows:
a. lens thickness
b. power in principal meridians
c. the power of the ADD
d. the lens diameter. Answer: b. power in principal meridians
◉ Increasing the diameter of a minus power lens always increases
its:
a. vertex power
b. center thickness
c. weight
d. refractive index. Answer: c. weight
◉ The optical center of a round segment is located:
,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. Answer: b. in the geometric
center of the segment
◉ The base curve of any multifocal lens is found on the surface
containing the:
a. cross curve
b. cylinder surface
c. segment
d. ocular curve. Answer: c. segment
◉ Normal slab-off (bicentric grind) is ground on the lens whose
vertical meridian has the:
a. strongest curves
b. most plus power
c. least plus power
d. least minus power. Answer: c. least plus power
,◉ The refractive error indicated by the Rx +1.75 -2.75 x 090 is:
a. compound hyperopic astigmatism
b. compound myopic astigmatism
c. simple myopic astigmatism
d. mixed astigmatism. Answer: d. mixed astigmatism
◉ Tempering a lens by heat treating results in a lens being:
a. less resistant to impact
b. more resistant to impact
c. more resistant to surface scratching
d. impossible to break. Answer: b. more resistant to impact
◉ A slab-off lens is for the correction of:
a. astigmatic errors
b. excessive weight of lens
c. excessive prism imbalance at the reading level
d. exotropia. Answer: c. excessive prism imbalance at the reading
level
, ◉ Chem-tempering makes a glass lens more impact 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. Answer: a. ion exchange
◉ Which wavelengths of light have been indicated as possible
contributors to the onset of cataracts?
a. 400-520 nm
b. 520-635 nm
c. 350-400 nm
d. 635-750 nm. Answer: c. 350-400 nm
◉ When the lenses are laid out and marked for cutting and 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
