ABO NOCE Basic Opticianry General Practice 4

Question 1

A frame has an A measurement of 50 mm and a DBL of 20 mm. The patient's monocular PD is 31 mm. How much decentration is required per lens?

Accepted Answer

4 mm nasal decentration

Answer

Frame geometric center to lens center = (A + DBL)/2 = (50+20)/2 = 35 mm; decentration = 35 − 31 = 4 mm nasally.

Question 2

Segment height for a flat-top bifocal is typically measured from the lowest rim of the frame to:

Accepted Answer

The lower margin of the pupil

Answer

Flat-top bifocal seg height places the segment top at the lower pupil margin for standard fitting.

Question 3

Which lens treatment provides the greatest blockage of UV radiation?

Accepted Answer

Photochromic lenses in their darkened (activated) state

Answer

Fully activated photochromic lenses block essentially 100% of UVA and UVB radiation.

Question 4

A metal frame sits too low on the patient's nose. The optician should:

Accepted Answer

Increase the splay angle of the nose pads (open them outward)

Answer

Opening the nose pads outward (increasing splay) raises the frame by changing the pad contact position on the nose.

Question 5

The Maddox rod test is used primarily to:

Accepted Answer

Detect and measure phorias (latent muscle imbalances)

Answer

The Maddox rod dissociates the eyes by converting a point light into a streak, revealing latent phorias.

ABO NOCE Basic Opticianry Practice Test