Download SVHS ADVANCED BIOLOGY NAME: 9th edition PERIOD: 1 2 3 4 5

SVHS ADVANCED BIOLOGY
9th edition
NAME: ____________________
PERIOD:
1 2 3 4 5 6
D.R. # 12.4 – HOW THE EYE SEES
After reading page 327 titled “Image Formation and Binocular Vision”;
1.
List the three processes necessary to focus a clear image on the retina of the eye.
a.
b.
c.
2. Bending of light rays called ______________ by the eye needs to occur if the object is less
_________________ away.
3. What percent of total refraction is due to light passing through the;
cornea?
_________
lens?
_________
4. How is the image different as it hits the retina compared to the real life object?
After reading page 329 titled “Accommodation”;
5. What term refers to an increase in the curvature of the lens thus increasing refraction? _____________
6. When looking at distant objects (20 feet or more) the lens needs to be flat. Explain how the eye
accomplishes the flattening of the lens.
7. When looking at something less than 20 feet away, the lens must thicken. Explain how the eye
accomplishes the thickening of the lens.
Looking at Figure 12.10 on page 330;
8. In order for the image to be seen clearly, the image must be focused on the retina. This is shown in “a”.
a.
What figure shows an eye that is farsighted?
What name describes this?
Where is the image focused in the eye?
What type of lens corrects this?
b. What figure shows an eye that is nearsighted?
Where is the image focused in the eye?
What name describes this?
What type of lens corrects this?
9. Irregular curvature of the cornea or lens is referred to as ________________________.
10. Describe two functions of the pupil.
a.
b.
11. Explain what convergence is and how it is accomplished.
12. What does convergence allow to happen regarding our vision?
After reading page 331 titled “Visual Pathway”;
13. Fully label the diagram to the right.
14. After rods and cones create nerve impulses,
what neuron carries them from the eye?
________________________
15. What percentage of the axons actually cross over at
the optic chiasma?
__________________
16. Counting the rods or cones, how many neurons make up the
visual pathway? (from rods to occipital lobe)
___________________