Study Questions: Optics and the Eye




1.  What are the two ways to describe light?

2.  Sketch a human eye and label important structures.

3.  Give brief definitions for the following optical phenomena: reflection, refraction, diffraction, and dispersion. Describe how each phenomenon is involved in forming the retinal image.

4.  What is "optical power"? Which parts of the eye have this ability? Which one of them is able to change the optical power?  How? Draw a convex lens and then draw another one which has stronger optical power then the previous one.

5.  Name four surface boundaries (i.e., places where the medium changes) in the eye which refract light. Which has the highest refractive power?  Why?

6.  Define accomodation.  Which part of the eye serves this function? How does its shape change with the distance between you and the object you are looking at?

7.  Which part of the eye contributes to each of the following phenomena: myopia, hyperopia, presbyopia, astigmatism, cataract.

8.  Briefly describe (e.g., with a diagram) focusing by the lens and the optical aberrations of myopia, hyperopia, and astigmatism. What kinds of lens are used to correct myopia and hyperopia, respectively?

9.  Discuss the function of the pupil.  In other words, give all the reasons, both optical and physiological, that it is wide open at certain times and closed down at others.

10.  What is depth of field? What causes the depth of field to change? Which part of the eye has this function?

11.  Define "conjugate eye movements". Briefly describe two types of conjugate eye movements.

12.  Define "disjunctive eye movements". Briefly describe two types of disjunctive eye movements.