NOCE - National Opticianry Competency Examination Dispensing Procedures and Instrumentation Questions and Answers

Question 1

A patient wearing progressive addition lenses complains that they have to tilt their head down to see distant objects clearly. Which of the following is the MOST likely cause of this issue?

Accepted Answer

The fitting height is too high.

Answer

If the fitting height of a progressive lens is set too high, the patient's pupils will be positioned too far up in the lens corridor. This forces them to tilt their head downward to look through the distance portion of the lens, which is located at the top.

Question 2

When using a manual lensometer to verify a prescription containing prism, the reticle target is displaced from the center. What is the correct initial procedure to measure the amount and direction of the prism?

Accepted Answer

Use the prism compensating device to bring the target to the center of the reticle.

Answer

A manual lensometer is equipped with a prism compensating device specifically designed to measure prism. By adjusting this device, the dispenser can move the reticle target back to the center, and the amount and direction of the prism can be read directly from the prism scale.

Question 3

Which instrument is considered the gold standard for accurately measuring a patient's interpupillary distance (PD)?

Accepted Answer

A pupilometer

Answer

A pupilometer is a specialized instrument that measures the distance between the pupils with high accuracy by using a corneal reflection system. While a millimeter ruler can be used, it is more prone to parallax and other human errors, making the pupilometer the most precise and reliable tool for this measurement.

Question 4

A patient selects a frame that, when adjusted, will sit 16 mm from their cornea. The original refraction was performed at a vertex distance of 11 mm. The prescription is -9.50 D sphere. What dispensing procedure is critical to ensure the patient experiences the correct lens power?

Accepted Answer

Order the lenses with a compensated power calculation.

Answer

When the vertex distance at which a patient wears their glasses differs significantly from the refraction vertex distance, especially with higher prescriptions (generally over +/- 7.00 D), the effective power of the lens changes. Moving a minus lens further from the eye makes it effectively stronger (more minus). A compensated power calculation must be performed to adjust the ordered lens power so the patient perceives the intended refractive correction.

Question 5

During the final fitting of a pair of metal-framed spectacles, the dispenser notices the bottom of the frame front is angled too far away from the patient's cheeks. Which adjustment should be made?

Accepted Answer

Increase the pantoscopic tilt.

Answer

Increasing the pantoscopic tilt involves angling the bottom of the frame front closer to the patient's cheeks. This adjustment is typically made by carefully bending the temples downwards at the hinge or endpiece. This ensures the lens is properly positioned for optimal optics, especially for multifocal lenses.

NOCE - National Opticianry Competency Examination Practice Test

NOCE - National Opticianry Competency Examination Practice Test

NOCE - National Opticianry Competency Examination Dispensing Procedures and Instrumentation Questions and Answers