ABO NOCE Basic Opticianry Ophthalmic Optics and Principles 5

Question 1

What type of lens corrects presbyopia by providing different optical zones for distance and near vision?

Accepted Answer

Bifocal lens

Answer

A bifocal lens has two distinct optical zones—one for distance and one for near—to compensate for the loss of accommodation in presbyopia.

Question 2

What is the 'add power' in a progressive lens prescription?

Accepted Answer

The additional plus power for near vision over the distance Rx

Answer

Add power is the additional plus power required for near vision, added to the distance prescription to compensate for reduced accommodation.

Question 3

Which of the following is true about total internal reflection?

Accepted Answer

It occurs when the angle of incidence exceeds the critical angle in a denser medium

Answer

Total internal reflection occurs when light in a denser medium strikes the boundary at an angle greater than the critical angle, causing all light to reflect back.

Question 4

A prism base-down before the right eye would cause the image to appear displaced in which direction?

Accepted Answer

Up

Answer

A prism displaces images toward the apex; base-down means the apex is up, so the image appears displaced upward.

Question 5

What does the term 'sag' (sagitta) refer to in ophthalmic lens design?

Accepted Answer

The depth of a curved surface measured from its chord

Answer

The sag (sagitta) is the perpendicular depth from the chord of a curved surface to the surface itself, important for calculating lens thickness.

ABO NOCE Basic Opticianry Practice Test

ABO NOCE Basic Opticianry Practice Test

ABO NOCE Basic Opticianry Ophthalmic Optics and Principles 5