Chapter 3 Pt. 1-2

Question 1

vision is based on what type of energy

Answer 1

visible light (light energy or photons from the environment)

Question 2

electromagnetic spectrum

Answer 2

electrical energy spreading microscopic waves

most perceived light comes from reflected light and show colors based on electromagnetic spectrum

Question 3

wavelengths

Answer 3

distance between peaks of electromagnetic waves

Question 4

visible light to humans (in nm)

Answer 4

400 to 700 nm

Question 5

color of shorter wavelengths

Answer 5

blue

Question 6

color of medium wavelengths

Answer 6

green

Question 7

color of longer wavelengths

Answer 7

yellow / orange / red

Question 8

pupil

Answer 8

an opening for light to enter

Question 9

iris

Answer 9

muscle that can make pupil dilate or constrict

Question 10

cornea

Answer 10

nonadjustable clear part covering the front

80% of where images are focused

Question 11

lens

Answer 11

adjustable to deal with distance

20% if where images are focused

Question 12

ciliary muscles

Answer 12

help shape the lens to focus on far and close objects

changes the lens

Question 13

retina

Answer 13

back of the eye containing rods and cones

Question 14

optic nerve

Answer 14

sends electrical signals to the brain

Question 15

rods

Answer 15

represent photoreceptors

large, cylinder shape

Question 16

cones

Answer 16

represent photoreceptors

small, cone-like

Question 17

what is the outer segment of the retina?

Answer 17

visual pigments

Question 17

visual pigments

Answer 17

react to light and create electrical signals to optic nerve

chemical for colors

Question 18

fovea

Answer 18

aka macula

small area containing only cones

the area that you look directly at is where fovea is located

Question 19

photoreceptor distribution in fovea

Answer 19

50,000 cones

Question 20

peripheral retina

Answer 20

outside of fovea

contains more rods than cones

Question 21

photoreceptor distribution in peripheral retina

Answer 21

120 mil rods

6 mil cones

Question 22

macular degeneration

Answer 22

when fovea is destroyed, people are unable to see the direct center (only) of what they are looking at

Question 23

reitinitis pigmentosa

Answer 23

poor peripheral vision

degeneration of retina passed on from one generation to another

in severe cases, not only do rods get attacked but cones in fovea do too, causing blindness

Question 24

blind spot

Answer 24

area where there is absence of retina and visual receptors located near optic nerve

Question 25

why is our blind spot not noticeable? review demos (fig. 3.7 and 3.8 on p. 43)

Answer 25

it is off the visual field where objects aren't sharply focused brain fills in the blind spot

Question 26

accommodation

Answer 26

unconscious adjustment of lens's shape to focus image

Question 27

what happens to lenses when ciliary muscles tighten?

Answer 27

lens bend (thicker curvature) focus on near object

Question 28

what happens to lenses when ciliary muscles relax?

Answer 28

lens flatten (thinner curvature) focus on far objects

Question 29

near point

Answer 29

point at which a close object can precisely reach the retina so that it can be seen clearly

Question 30

far point

Answer 30

point at which a far object can precisely reach retina so that it can be seen clearly

Question 31

refractive errors

Question 32

is accommodation foolproof? why?

Question 33

presbyopia

Question 34

myopia

Question 35

two possible problems for myopia

Question 36

hyperopia

Question 37

how do photoreceptors process light energy?

Question 38

transduction

Question 39

what are visual pigment molecules and where are they located?

Question 40

molecule

Question 41

two parts of a visual pigment molecule

Question 42

isomerization (+ what happens when it occurs?)

Question 43

dark adaptation

Question 44

threshold

Question 45

sensitivity

Question 46

three adaptation curves

Question 47

visual pigment bleaching

Question 48

visual pigment regeneration

Question 49

how long do cones and rods regenerate their pigments?

Question 50

two important relationships between perception and physiology when examining visual pigment regeneration