ABO NOCE Basic Opticianry Spectacle Dispensing and Fitting 5

Question 1

The primary purpose of the distance between lenses (DBL or bridge size) measurement is to:

Accepted Answer

Ensure the frame fits the patient's nose bridge

Answer

The DBL (distance between lenses) corresponds to the bridge size and ensures the frame fits comfortably and correctly on the patient's nose.

Question 2

Induced prism resulting from a patient looking through a point other than the optical center is calculated using:

Accepted Answer

Prentice's Rule

Answer

Prentice's Rule states that prism (in prism diopters) = decentration (cm) × lens power (diopters), and is the standard formula for calculating induced prism.

Question 3

A patient with a +3.00D right lens and +3.00D left lens has their glasses slide down 4mm on the nose. How much vertical prism is induced in each lens?

Accepted Answer

1.2Δ base down each eye

Answer

Using Prentice's Rule: 0.4cm × 3.00D = 1.2Δ; when plus lenses slide down, the pupil is above OC, inducing base-down prism — wait, the OC drops below pupil inducing base-up... actually when glasses slide down, pupil is above OC for plus lens = base-down. Re-checking: P = cF = 0.4 × 3 = 1.2Δ base-down in each eye.

Question 4

Which frame adjustment corrects a frame that sits too close to the eyelashes on one side?

Accepted Answer

Increase the splay angle of the nose pad on the affected side

Answer

Increasing the splay (flare) angle of the nose pad on the side where lashes touch pushes that side of the frame away from the face.

Question 5

For a patient requiring a flat-top 35 bifocal, which minimum B measurement is generally recommended for the frame?

Accepted Answer

35mm

Answer

A flat-top 35 bifocal is 35mm wide and requires a frame with a B measurement of at least 35mm to accommodate the segment properly.

ABO NOCE Basic Opticianry Practice Test

ABO NOCE Basic Opticianry Practice Test

ABO NOCE Basic Opticianry Spectacle Dispensing and Fitting 5