FREE ABO Optics and Refraction Questions and Answers

Question 1

A patient's refraction is -4.50 +1.00 x 090. To correct this refractive error, what type of lens is required?

Accepted Answer

A sphero-cylindrical concave lens

Answer

A plano-convex lens

Answer

A biconvex lens

Answer

A sphero-cylindrical convex lens

Question 2

A patient has a steep vertical corneal meridian and a flat horizontal meridian. This type of astigmatism is known as:

Accepted Answer

With-the-rule astigmatism

Answer

Against-the-rule astigmatism

Answer

Oblique astigmatism

Answer

Irregular astigmatism

Question 3

Snell's Law (n1 * sin(θ1) = n2 * sin(θ2)) is a fundamental principle in optics that describes:

Accepted Answer

The refraction of light as it passes between two different media.

Answer

The relationship between focal length and lens power.

Answer

The diffraction of light as it passes through a small aperture.

Answer

The reflection of light from a smooth surface.

Question 4

What is the primary physiological cause of presbyopia?

Accepted Answer

Decreased elasticity and hardening of the crystalline lens.

Answer

Weakening of the ciliary muscle.

Answer

Elongation of the axial length of the eye.

Answer

Flattening of the corneal curvature.

Question 5

During retinoscopy on an uncorrected myopic eye, the examiner working at a standard distance will observe:

Accepted Answer

"Against" motion when working outside the far point.

Answer

"With" motion when working outside the far point.

Answer

"Against" motion when working inside the far point.

Answer

No reflex motion.

Question 6

The effect of vertex distance is most clinically significant when prescribing spectacles for which of the following refractive errors?

Accepted Answer

-12.00 D sphere

Answer

-1.50 D sphere

Answer

+2.00 D sphere

Answer

+3.00 D sphere with +1.00 D cylinder

Question 7

A Jackson Cross Cylinder (JCC) is used during subjective refraction to:

Accepted Answer

Refine the axis and power of the astigmatic correction.

Answer

Determine the spherical equivalent.

Answer

Measure the accommodative amplitude.

Answer

Neutralize the retinoscopy reflex.