NAO EXAM QUESTIONS AND
DETAILED ANSWERS. EXPERT
VERIFIED FOR GUARANTEED PASS.
The correct transposed RX for -1.00-.50x37 is? - ANS -1.50 + 0.50 x 127
The correct transposition for +2.00 -2.00 x 060 is? - ANS Plano +2.00 x 150
An uncut lens must be at least _______ mm in diameter to allow the edging of a 54 mm round
lens decentered 3 mm in: - ANS 60 mm
A +3.00 sphere lens has a front base curve of +6.25. What is the back surface curve? - ANS -
3.25
A -2.00 -1.00 x 045 lens has a front base curve of +6.25. What are the back surface curves? -
ANS -8.25 -1.00
Moving the optical center of a plus lens inward from the correct PD results in _____ -
ANS Base in prism
Where will the optical center appear in a lensometer when neutralizing a left lens for base in
prism? - ANS To the left of the target center
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
, Glazing is a term used to indicate _____ - ANS A defect that occurs when an anti-reflective
lens is tinted
Frequently, bicentric grinding (slab-off) is used as a means of obtaining prism in the reading
field to correct induced prism imbalance. The usual correction during the fabrication process is
achieved by grinding prism in the following direction: - ANS up
A patient stops in to see you for adjustment of his glasses. After careful inspection you find the
only thing wrong that there is too much pantoscopic tilt. To make the necessary adjustment
you will: - ANS Angle the temples upward from the end pieces
If the RX is +2.00 -4.00 x 135, it would be necessary to decenter the lens _____to create 1.00
prism base in : - ANS not possible
Rewrite the RX below, which is prescribed for a patient afflicted with double vision, so as to
make better balanced lenses:
OD -1.00 -0.50 x 090 5.00 BU
OS -1.25 - 0.50 x 090 1.00 BD - ANS OD -1.00 -0.50 x 090 3.00 prism BU
OS -1.25 -0.50x 090 3.00 prism BD
Correct the imbalance in the following prescription by use of slab-off. Reading level is 10 mm:
OD +5.00 -2.00 x 090
OS +2.25 -3.00 x 090 - ANS 2.25 prism BU in OS
You are fitting a patient with a stock frame, 24 DBL, 44 eve size and 137 mm skull temples. The
distance PD is only 62 mm. If by some unfortunate error the lenses are not decentered at all,
how much prism is created in each eye?
RX: OU -2.25 -1.50 x 045 - ANS 0.5 prism BI
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
DETAILED ANSWERS. EXPERT
VERIFIED FOR GUARANTEED PASS.
The correct transposed RX for -1.00-.50x37 is? - ANS -1.50 + 0.50 x 127
The correct transposition for +2.00 -2.00 x 060 is? - ANS Plano +2.00 x 150
An uncut lens must be at least _______ mm in diameter to allow the edging of a 54 mm round
lens decentered 3 mm in: - ANS 60 mm
A +3.00 sphere lens has a front base curve of +6.25. What is the back surface curve? - ANS -
3.25
A -2.00 -1.00 x 045 lens has a front base curve of +6.25. What are the back surface curves? -
ANS -8.25 -1.00
Moving the optical center of a plus lens inward from the correct PD results in _____ -
ANS Base in prism
Where will the optical center appear in a lensometer when neutralizing a left lens for base in
prism? - ANS To the left of the target center
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
, Glazing is a term used to indicate _____ - ANS A defect that occurs when an anti-reflective
lens is tinted
Frequently, bicentric grinding (slab-off) is used as a means of obtaining prism in the reading
field to correct induced prism imbalance. The usual correction during the fabrication process is
achieved by grinding prism in the following direction: - ANS up
A patient stops in to see you for adjustment of his glasses. After careful inspection you find the
only thing wrong that there is too much pantoscopic tilt. To make the necessary adjustment
you will: - ANS Angle the temples upward from the end pieces
If the RX is +2.00 -4.00 x 135, it would be necessary to decenter the lens _____to create 1.00
prism base in : - ANS not possible
Rewrite the RX below, which is prescribed for a patient afflicted with double vision, so as to
make better balanced lenses:
OD -1.00 -0.50 x 090 5.00 BU
OS -1.25 - 0.50 x 090 1.00 BD - ANS OD -1.00 -0.50 x 090 3.00 prism BU
OS -1.25 -0.50x 090 3.00 prism BD
Correct the imbalance in the following prescription by use of slab-off. Reading level is 10 mm:
OD +5.00 -2.00 x 090
OS +2.25 -3.00 x 090 - ANS 2.25 prism BU in OS
You are fitting a patient with a stock frame, 24 DBL, 44 eve size and 137 mm skull temples. The
distance PD is only 62 mm. If by some unfortunate error the lenses are not decentered at all,
how much prism is created in each eye?
RX: OU -2.25 -1.50 x 045 - ANS 0.5 prism BI
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
