NOCE Optical Instrumentation Usage Questions and Answers

Question 1

An optician is using a manual keratometer to measure the corneal curvature of a patient.
The horizontal meridian reading is 44.50 D and the vertical meridian reading is 42.75 D.
What does this finding indicate?

Accepted Answer

Against-the-rule astigmatism

Answer

With-the-rule astigmatism

Answer

Oblique astigmatism

Answer

A spherical cornea

Question 2

When using a digital pupillometer to take a monocular pupillary distance (PD) measurement for progressive lenses, the optician should instruct the patient to fixate on:

Accepted Answer

The light source within the instrument

Answer

A distant object directly in front of them

Answer

The optician's occluded eye

Answer

A near object held at 40 cm

Question 3

While verifying a prescription with a manual lensometer, the optician finds that the sphere lines come into focus at -1.50 D. After turning the power drum further, the cylinder lines come into focus at -3.00 D. To correctly identify the axis of the cylinder, what must be done?

Accepted Answer

Adjust the axis wheel until the three parallel cylinder lines appear straight and unbroken.

Answer

Rotate the power drum back and forth until both sets of lines are equally blurry.

Answer

Note the axis wheel reading when the sphere lines are in focus.

Answer

Center the target reticle using the prism compensation device.

Question 4

A patient is being evaluated for a soft contact lens fitting. Which slit lamp illumination technique is most effective for assessing the overall fit, including lens movement and centration, without causing excessive tearing?

Accepted Answer

Diffuse illumination with low to medium magnification

Answer

Sclerotic scatter

Answer

Specular reflection

Answer

Direct focal illumination with a narrow beam

Question 5

Which of the following is the first and most critical step an optician must perform before using a manual lensometer to ensure accurate readings for any patient's glasses?

Accepted Answer

Focusing the eyepiece for their own eye.

Answer

Placing the glasses with the temples facing away from the operator.

Answer

Setting the power drum to the approximate sphere power of the lens.

Answer

Turning the power drum to +10.00 to fog the target.

Question 6

An optician is neutralizing a lens and finds that the target mires cannot be centered in the reticle, even with the lens stage centered. The intersection of the mires is displaced 2 units up and 3 units to the left (toward the nose for a right lens). What instrument should be used to quantify this finding?

Accepted Answer

Prism compensating device

Answer

Geneva lens clock

Answer

Distometer

Answer

Pupilometer

An optician is using a manual keratometer to measure the corneal curvature of a patient.The horizontal meridian reading is 44.50 D and the vertical meridian reading is 42.75 D.What does this finding indicate?

An optician is using a manual keratometer to measure the corneal curvature of a patient.
The horizontal meridian reading is 44.50 D and the vertical meridian reading is 42.75 D.
What does this finding indicate?