Chapter 3, 3.4-3.6

Question 1

The 3 Aspects of our Perception of Light (3)

Answer 1

1) Brightness: amplitude of the wave
2) Color: hue, determined by length of the wave
3) Saturation: purity of the color, how much of certain wavelength is observed

Question 2

Cornea

Answer 2

clear membrane that protects the eye and focuses incoming light

Photo-reactive Keratectomy and LASIK procedures adjust the cornea changing its ability to focus light

Question 3

Aqueous humor

Answer 3

water-fluid layer that replenishes and supplies nourishment to the eye

Question 4

Pupil and iris

Answer 4

Iris is the muscle around the pupil, a hole, and works to manipulate the size changing the amount of light let in

Question 5

Lens

Answer 5

clear structure that finishes processing done by the cornea

Question 6

Visual accomodation

Answer 6

process where the lens changes between thick and thin to focus on objects that are far away

Question 7

Presbyopia

Answer 7

aging disorder where people lose the ability to perform visual accomodation

Question 8

Myopia

Answer 8

near-sightedness, elongated eye-shape causes the focal point to fall short

Question 9

Hyperopia

Answer 9

far-sightedness, condensed eye-shape causes focal point to fall beyond the retina

Question 10

Vitreous humor

Answer 10

jelly-like fluid past the lens, replenishes and nourishes the eye

Question 11

Retina (3 components)

Answer 11

light-sensitive area at the back of the eye containing:

1) Rods and cones
2) Ganglion cells
3) Bipolar cells

Question 12

Rods

Answer 12

visual sensory receptors in the periphery of the retina (really anywhere but the fovea) responsible for noncolor sensitivity and low levels of light

Question 13

Cones

Answer 13

visual sensory receptors in the center of the retina (fovea) responsible for color vision and clarity

Question 14

Bipolar cells

Answer 14

interneuron with one dendrite on one side and one axon on the other, the first receptors of rod and cone information

Question 15

Ganglion cells

Answer 15

neurons in the retina whose axons form the optic nerve

Question 16

The Blind Spot

Answer 16

hole in the retina where ganglion axons leave the retina to form the optic disk

Question 17

Visual fields (3 parts)

Answer 17

1) light entering the eye is separated into the left and right visual fields depending on which eye detects it
2) image is processed in the opposite side of the retina, leading to an upside-down projection
3) Despite “cross-wiring” our left and right visual cortexes and flip the image

Question 18

Dark adaptation

Answer 18

rods work to help the eye recover from going from a brightly-lit environment to a dark one (harder the brighter the initial stimuli)

eyes do this slower as we age

Question 19

Light adaptation

Answer 19

cones adapt to increased levels of light (much faster than dark adaptation)

Question 20

Trichromatic theory (founder and reviser, primary colors)

Answer 20

Young and revised by Hemholtz, theory that there are three types of cones: Red, Green, and Blue

different shades of colors are produced by different amounts of these lights being received and then speed of neuron firing

Question 21

Afterimages

Answer 21

images that persist for a brief time after the initial stimulus is removed

Question 22

Opponent-Process Theory (founder, primary colors, and how it explains Afterimages)

Answer 22

visual neurons are stimulated by the light of one color and inhibited by its pair

Red (+) and Green (-)
Blue (+) and Yellow (-)

When looking at an image, cells are stimulated to a certain color and eventually fatigue. When the image is removed, the fatigued cell overcompensates.

Question 23

Which theory?

Answer 23

Trichromatic Theory explains what’s happening with raw stimulus and the detection of light wavelengths.

Opponent-Process Theory explains aspects of visual perception that occur after the initial detection of light.

Question 24

Color blindness

Answer 24

color-deficient vision, defective cones in one’s eyes make it incapable of perceiving certain colors

Question 25

Types of color-deficient vision (3)

Answer 25

1) Achromatic or Monochromatic vision: cones do not function properly making everything black, white, or grey
2) Protanopia and Deuteranopia (most common): dichromatic vision where red or green cones don’t function properly, leading to perceiving the world in shades of blue, yellow, and grey
3) Tritanopia: dichromatic vision with blue-yellow deficiency, leading to perceiving the world in shades of red, green, and grey

Question 26

Sex-linked inheritance

Answer 26

the gene for color-deficient vision is attached to the sex chromosome, making it so women must inherit two recessive genes for CDV while men only need to inherit one