ABO NOCE Basic Opticianry Applying Prentice's Rule 2

Question 1

A lens has a power of +3.00 D. A patient's pupil is decentered 4 mm below the optical center. How much vertical prism is induced?

Accepted Answer

1.20Δ base up

Answer

1.20Δ base down

Answer

0.75Δ base down

Answer

0.75Δ base up

Question 2

Using Prentice's Rule, how much prism is induced when a -5.00 D lens is decentered 6 mm from the optical center?

Accepted Answer

3.00Δ

Answer

2.50Δ

Answer

0.83Δ

Answer

30.00Δ

Question 3

A patient requires 2.00Δ of prism. The available lens power is +4.00 D. How far must the lens be decentered to achieve this?

Accepted Answer

5 mm

Answer

8 mm

Answer

2 mm

Answer

0.5 mm

Question 4

Which unit for distance (d) must be used in Prentice's Rule formula Δ = P × d?

Accepted Answer

Centimeters

Answer

Millimeters

Answer

Meters

Answer

Prism diopters

Question 5

A frame PD is 68 mm and the patient's PD is 60 mm. The lens power is +2.50 D. How much horizontal prism is induced per eye if the decentration is split equally?

Accepted Answer

1.00Δ per eye

Answer

0.50Δ per eye

Answer

2.00Δ per eye

Answer

2.50Δ per eye

Question 6

For a -2.00 D lens, the optical center is decentered 10 mm nasally in front of the right eye. What is the prismatic effect and base direction?

Accepted Answer

2.00Δ base out

Answer

2.00Δ base in

Answer

0.20Δ base in

Answer

0.20Δ base out

Question 7

A bifocal add of +2.50 D has its segment center 3 mm below the add's optical center. What is the vertical prismatic effect at the segment center?

Accepted Answer

0.75Δ base down

Answer

0.75Δ base up

Answer

5.00Δ base up

Answer

0.50Δ base up