FREE National Opticianry Competency Exam (NOCE) Ophthalmic Optics and Lenses Questions and Answers

Question 1

A patient's prescription is -5.00 D sphere. If the patient looks through the lens 4 mm below the optical center, what is the amount and direction of the induced prism?

Accepted Answer

2.0 Δ Base Up

Answer

2.0 Δ Base Down

Answer

1.25 Δ Base Up

Answer

1.25 Δ Base Down

Question 2

Which of the following lens materials has the highest Abbe value, indicating the least amount of chromatic aberration?

Accepted Answer

CR-39

Answer

Polycarbonate

Answer

High-Index 1.67

Answer

Trivex

Question 3

A patient with anisometropia requires a slab-off prism to correct for vertical imbalance at the reading level. On which lens is a conventional slab-off typically ground?

Accepted Answer

The lens with the most minus or least plus power in the vertical meridian.

Answer

The lens with the most plus power in the vertical meridian.

Answer

The lens with the least minus power in the vertical meridian.

Answer

The lens with the highest cylinder power.

Question 4

What is the resulting prescription when +1.75 -2.50 x 085 is transposed?

Accepted Answer

-0.75 +2.50 x 175

Answer

-1.25 +2.50 x 175

Answer

+4.25 -2.50 x 175

Answer

-0.75 -2.50 x 175

Question 5

According to ANSI Z87.1 standards for basic impact safety lenses, what is the minimum thickness required for a high-index plastic lens?

Accepted Answer

3.0 mm

Answer

2.0 mm

Answer

2.5 mm

Answer

2.2 mm

Question 6

A primary advantage of an aspheric lens design compared to a standard spherical lens is that it:

Accepted Answer

provides a wider field of clear vision with less peripheral distortion.

Answer

is easier to manufacture.

Answer

increases chromatic aberration.

Answer

is only available in glass material.

A patient's prescription is -5.00 D sphere.If the patient looks through the lens 4 mm below the optical center, what is the amount and direction of the induced prism?

A patient's prescription is -5.00 D sphere.
If the patient looks through the lens 4 mm below the optical center, what is the amount and direction of the induced prism?