ABO NOCE Basic Opticianry General Practice 2

Question 1

A patient's prescription reads +2.50 -1.00 x 090. What is the spherical equivalent?

Accepted Answer

+2.00

Answer

Spherical equivalent = sphere + (cylinder/2) = +2.50 + (-0.50) = +2.00.

Question 2

Which frame measurement represents the longest horizontal dimension of a single lens aperture?

Accepted Answer

A measurement (eye size)

Answer

The A measurement is the horizontal width of one lens opening in the frame.

Question 3

Prentice's Rule states that prismatic effect (in prism diopters) equals:

Accepted Answer

Power (D) × decentration (cm)

Answer

Prentice's Rule: Δ = P(D) × d(cm); decentration must be expressed in centimeters.

Question 4

When transposing a minus-cylinder prescription to plus-cylinder form, the new axis is:

Accepted Answer

Original axis ± 90°

Answer

Transposition to the opposite cylinder form requires rotating the axis by 90 degrees.

Question 5

A frame marked 54-18-140 has what bridge size?

Accepted Answer

18 mm

Answer

In standard frame notation (eye size–bridge–temple length), the middle number (18) is the bridge width.

ABO NOCE Basic Opticianry Practice Test