NOCE Dispensing and Fitting Procedures 3

Question 1

Which ANSI Z80.1 tolerance applies to the spherical power of a finished ophthalmic lens with a prescription of -4.00 D sphere?

Accepted Answer

±0.13 D

Answer

ANSI Z80.1 allows ±0.13 D tolerance for spherical powers between -3.375 D and -6.375 D.

Question 2

A patient with anisometropia requires the optical centers of the lenses to be at different heights. This is best described as:

Accepted Answer

Slab-off correction

Answer

Slab-off (or reverse slab-off) grinds prism into the reading zone of one lens to equalize the vertical imbalance caused by anisometropia.

Question 3

During frame selection, you notice a patient has a very narrow nose bridge. Which frame feature should you prioritize?

Accepted Answer

Adjustable nose pads on pad arms

Answer

Adjustable nose pads on pad arms allow precise customization to fit a narrow nasal bridge securely and comfortably.

Question 4

When fitting a bifocal lens, the standard placement for the flat-top segment top is:

Accepted Answer

At the lower limbus of the eye

Answer

The standard flat-top bifocal segment top is placed at the lower limbus so it is accessible in downgaze without disrupting distance vision.

Question 5

A patient experiences swim and distortion when wearing new progressive lenses. Which adjustment is MOST likely to help?

Accepted Answer

Adjust pantoscopic tilt to match the prescribed value

Answer

Correcting pantoscopic tilt aligns the progressive lens zones to the patient's line of sight, reducing peripheral swim and distortion.

NOCE - National Opticianry Competency Examination Practice Test