Chapter 3b Vision

Question 1

Cornea

Answer 1

A thin transparent cover for the whole eye (Figure 3.4). The cornea refracts (or bends) images to improve vision

Question 2

Iris

Answer 2

A colored circular muscle situated in the center of the eye. The iris gives your eyes their unique shade;

They let in the correct amount of light

Question 3

Pupil

Answer 3

The opening in the middle. The size of the pupil determines how much light the eye allows through.

Question 4

Lens

Answer 4

A clear layer beneath the surface of your eye that maintains focus on an object by varying its own shape

Question 5

Visual accommodation

Answer 5

The process by which the lens changes shape to focus on objects at varying distances from your eyes.

Question 6

Retina

Answer 6

The rear part of the eyeball that receives visual stimulation and sends it to the brain via the optic nerve

Performs visual transduction

Question 7

Optic Nerve

Answer 7

Delivers visual information from the retina to the brain.

Question 8

Rods

Answer 8

Are receptor cells in the retina that detect shades of gray and allow us to see in low light.

Question 9

Cones

Answer 9

Are receptor cells in the retina that detect color when light is plentiful.

Question 10

Fovea

Answer 10

An area in the center of the retina that contains many cones but no rods.

Question 11

Blind spot

Answer 11

The part of the retina that contains no rods or cones, which means it can’t sense light. The blind spot is basically the part of the retina where the optic nerve connects

Question 12

Monocular depth cues

Answer 12

Qualities of visual stimuli that indicate depth when you use only one eye. Monocular depth cues are the kinds of things you notice in a two-dimensional painting or photograph

Question 13

Binocular depth cues

Answer 13

Qualities of visual stimuli that indicate depth when you use both eyes. Binocular depth cues help us when we look at things in three dimensions

Question 14

Retinal disparity (or stereopsis )

Answer 14

Your brain’s measurement of the difference between the images of a single object sent by each of your two eyes. Retinal disparity is greater for objects that are close up than for objects that are far away.

Question 15

hue

Answer 15

The color of light, as determined by its wavelength.

Question 16

Trichromatic theory of color vision

Answer 16

An explanation of color vision based on the idea that your cones are specialized to sense either red, green, or blue

Question 17

opponent-process theory of color vision

Answer 17

an explanation of color vision based on the idea that your visual system is specialized to sense specific opposite pairs of colors (like red–green, blue–yellow.).

Question 18

Figure–ground organization

Answer 18

your tendency to visually distinguish between an object and its background.

Question 19

Gestalt

Answer 19

an organized whole that you perceive as different from just the sum of its parts.