Chapter 3

Question 1

is light a particle or a wave?

Answer 1

both!

Question 2

visible light has wavelengths from about ___ - ____

Answer 2

400-700 nm

Question 3

the ___ the wavelength, the higher the power

Answer 3

shorter

Question 4

give 3 examples of wavelengths too short to see, but very powerful

Answer 4

1. gamma rays (shortest)
2. x-ray (next)
3. UV rays (next)

Question 5

give four examples of 4 rays with wavelengths too long to see

Answer 5

1. infrared (shortest)
2. radar (next)
3. broadcast brands (next)
4. AC circuits (next)

Question 6

does white absorb a little or a lot of light?

Answer 6

a little

Question 7

what makes a leaf green?

Answer 7

it reflects green light (medium wavelength light)

Question 8

when an object is near, the eye is ____

Answer 8

relaxed

Question 9

Accommodation to bring the focus point forward (for near objects) involves _____, which ______ on the suspensory ligaments, allowing the lens to become ______, increasing its refractive power.

Answer 9

contracting the ciliary muscles

reduces tension

rounder or “fatter”

Question 10

the focusing power of the eye is 80% __ and 20% ____

Answer 10

80% cornea and 20% lens

Question 11

what is presbyopia? how do you treat it?

Answer 11

presbyopia - happens when you get older and your lens gets harder - your near point moves farther away, and your ciliary muscles can only contract so much.

treatment: bifocal glasses

Question 12

thin lens = __ light bending = ___ objects

Answer 12

thin lens = little light bending = far objects

Question 13

fat lens = __ light bending = ___ objects

Answer 13

fat lens = a lot of light bending = near objects.