NOCE Ophthalmic Optics and Formulas Questions and Answers

Question 1

A patient's prescription is +10.50 D sphere.
The refraction was performed at a vertex distance of 12 mm, but the patient's chosen frame will sit at 17 mm.
What is the compensated lens power that should be ordered?

Accepted Answer

+11.00 D

Answer

+10.00 D

Answer

+10.50 D

Answer

+9.95 D

Question 2

A patient is looking 5 mm below the optical center of a lens with the prescription -4.00 -2.00 x 180. According to Prentice's Rule, what is the amount and direction of the vertical prism induced?

Accepted Answer

2.0 Δ Base Up

Answer

2.0 Δ Base Down

Answer

3.0 Δ Base Up

Answer

3.0 Δ Base Down

Question 3

Which of the following represents the correct transposition of the prescription +1.75 +2.50 x 080?

Accepted Answer

+4.25 -2.50 x 170

Answer

+4.25 +2.50 x 170

Answer

-0.75 -2.50 x 170

Answer

-0.75 +2.50 x 080

Question 4

What is the spherical equivalent of the prescription -3.50 -2.50 x 120?

Accepted Answer

-4.75 D

Answer

-2.25 D

Answer

-6.00 D

Answer

-3.50 D

Question 5

A lens has a focal length of -40 cm. What is its power in diopters?

Accepted Answer

-2.50 D

Answer

+2.50 D

Answer

+0.025 D

Answer

-0.025 D

Question 6

A lab order requires compounding 3.0 Δ Base In and 2.0 Δ Base Up for the right eye. What is the approximate resultant prism and axis?

Accepted Answer

3.60 Δ @ 034°

Answer

5.00 Δ @ 056°

Answer

5.00 Δ @ 034°

Answer

3.60 Δ @ 146°

A patient's prescription is +10.50 D sphere.The refraction was performed at a vertex distance of 12 mm, but the patient's chosen frame will sit at 17 mm.What is the compensated lens power that should be ordered?

A patient's prescription is +10.50 D sphere.
The refraction was performed at a vertex distance of 12 mm, but the patient's chosen frame will sit at 17 mm.
What is the compensated lens power that should be ordered?