AOA Optics and Refraction

Question 1

In an eye with simple myopia, the far point is located:

Accepted Answer

At a finite distance in front of the eye

Answer

At optical infinity behind the retina

Answer

On the retina itself

Answer

At the anterior focal point of the eye

Question 2

When performing retinoscopy, a 'with' reflex indicates that the eye's far point is:

Accepted Answer

Behind the examiner (hyperopia or low myopia)

Answer

In front of the examiner (high myopia)

Answer

At the examiner's working distance (neutrality)

Answer

Unrelated to the far point location

Question 3

The principal effect of a minus cylinder lens is to:

Accepted Answer

Reduce power in one meridian while leaving the other unchanged

Answer

Increase power equally in all meridians

Answer

Rotate the axis of astigmatism by 90°

Answer

Reduce power equally in all meridians

Question 4

Chromatic aberration in the eye is primarily responsible for which clinical phenomenon?

Accepted Answer

Blue light focusing slightly anterior to red light (longitudinal chromatic aberration)

Answer

Prism effect at the lens periphery causing rainbows

Answer

Increased glare sensitivity in mesopic conditions

Answer

Reduced contrast sensitivity at spatial frequencies above 10 cpd

Question 5

The power of a thin lens required to correct a 4D myope is:

Accepted Answer

-4.00 D

Answer

+4.00 D

Answer

-2.00 D

Answer

+2.00 D

Question 6

Astigmatism is defined as a refractive condition in which:

Accepted Answer

The eye has different powers in different meridians

Answer

The eye has no definite focal point

Answer

Both eyes have equal refractive errors

Answer

The cornea is uniformly too steep for the axial length