ABO NOCE Basic Opticianry Ophthalmic Optics Questions and Answers 5

Question 1

The optical cross is a diagram used to represent:

Accepted Answer

The power in two principal meridians of a spherocylindrical lens

Answer

An optical cross shows the power in each of the two principal meridians (90° apart) of a spherocylindrical lens.

Question 2

When comparing two lenses of equal power, the lens with a higher refractive index will be:

Accepted Answer

Thinner and lighter

Answer

Higher refractive index materials bend light more per unit of surface curvature, allowing flatter, thinner lens designs.

Question 3

The lensometer (focimeter) measures a lens by finding the position where:

Accepted Answer

The target image is focused at a fixed reference point corresponding to a specific vergence

Answer

The lensometer neutralizes the lens power by finding the position where the target appears clear, corresponding to the vergence added by the lens.

Question 4

Oblique astigmatism as a lens aberration is different from astigmatism in a prescription because it:

Accepted Answer

Is introduced by the lens itself when viewing off-axis, not from the eye's refractive error

Answer

Oblique (marginal) astigmatism is a lens aberration occurring when light passes through the peripheral zone at an angle, unrelated to the wearer's astigmatism.

Question 5

The reduced eye model simplifies the eye to a single refracting surface with a refractive index of approximately:

Accepted Answer

1.336

Answer

The reduced eye model uses a single refracting surface with the refractive index of the ocular media, approximately 1.336.

ABO NOCE Basic Opticianry Practice Test

ABO NOCE Basic Opticianry Practice Test

ABO NOCE Basic Opticianry Ophthalmic Optics Questions and Answers 5