Board Certified Ophthalmologist FREE Optics and Refraction Questions and Answers 2

Question 1

A patient with a cycloplegic refraction of +5.00 D requires a spectacle lens at a vertex distance of 12 mm. What is the effective power at the corneal plane?

Accepted Answer

+5.31 D

Answer

+4.72 D

Answer

+5.00 D

Answer

+4.50 D

Question 2

Which type of astigmatism is present when one focal line falls in front of the retina and the other falls behind it?

Accepted Answer

Mixed astigmatism

Answer

Simple myopic astigmatism

Answer

Compound hyperopic astigmatism

Answer

Simple hyperopic astigmatism

Question 3

What is the critical angle for total internal reflection at a crown glass-air interface if the refractive index of crown glass is 1.52?

Accepted Answer

41.1 degrees

Answer

48.8 degrees

Answer

33.3 degrees

Answer

55.6 degrees

Question 4

A prism with an apical angle of 10 degrees and refractive index of 1.5 produces what amount of deviation?

Accepted Answer

5 prism diopters

Answer

10 prism diopters

Answer

15 prism diopters

Answer

7.5 prism diopters

Question 5

In retinoscopy, a with-the-rule movement is observed in the horizontal meridian. What type of lens should be added to neutralize this meridian?

Accepted Answer

Plus cylinder at 180 degrees

Answer

Minus cylinder at 180 degrees

Answer

Plus cylinder at 90 degrees

Answer

Plus sphere only

Question 6

What is the approximate accommodative demand for a 2.50 D myope who removes their spectacles to read at 40 cm?

Accepted Answer

0 D

Answer

2.50 D

Answer

1.50 D

Answer

4.00 D