Study Guide for Chapter 2

Be sure that you can identify and define the key terms on page 69.

1.         Why is light (electromagnetic radiation in the visible spectrum) the stimulus for vision? (OK, I’ll give you this one: It is found in great abundance, it provides almost instantaneous information, and it retains geometric relationships within and between objects.)

2.         What do your authors mean when they say light is the carrier of information and not usually the stimulus of interest? What is "inverse optics?"

3.         What are the advantages of having frontally placed eyes rather than laterally placed ones?

4.         Why is it advantageous for us to be able to move our eyes?

5.         You should know the six extraocular muscles, their anatomical positions, and what directions they move the eyes (including convergently and divergently).

6.         How is the eye protected from injury?

7.         What mechanism was hypothesized by Volkman, Riggs, and Moore (1980) to prevent us from experiencing “blackouts” during eyeblinks? Was this hypothesis supported?

8.       What are the three concentric layers of the eye?

9.       You should know the anatomy of the eye. We will cover this in relative detail in class; make certain you are very comfortable with this. The information is covered on pages 41-49. If you need additional help with it, come see me immediately.

10.       Understanding the anatomy of the eye helps us to detect and treat certain disorders before they progress too far. Explain how such disorders as glaucoma, diabetic retinopathy, macular degeneration, retinitis pigmentosa, and cataracts impair vision. How preventable and/or treatable are these conditions?

11.       What is a retinal image?

12.       What is the difference between emitted and reflected light?

13.       What do abrupt changes in reflectance usually signify about an object? What about gradual changes? How are highlights formed?

14.       What two factors determine the sharpness of an image on the retina?

15.       What effect does divergent light have on the retinal image? What type of lens counteracts this divergence?

16.       Compare emmetropia with myopia and hyperopia. What is anomalous myopia? What is presbyopia?

17.       What produces astigmatism? How is it corrected?

18.      You should have a firm understanding of the layers of the retina, including which cells are found where. This is covered not only in your text, but also in class.

19.       How is the process of phototransduction accomplished? Again, this is covered in your text and in class so you should know it in a fair amount of detail.