3.2 Vision: seeing the light

Question 1

Cornea

Answer 1

A transparent covering on the eyes surface through which light enters.

Question 2

Iris

Answer 2

The pigmented, circular muscle in the eye that regulates the size of the pupil to adjust to changes in the level of illumination.

Question 3

Pupil

Answer 3

The black opening inside the iris that allows light to enter the eye.

Question 4

Lens

Answer 4

The structure in the eye that focuses light rays on the retina.

Question 5

Accomidation

Answer 5

The process by which the lens changes its shape to focus images more clearly on the retina.

Question 6

Retina

Answer 6

The light sensitive layer of the inner surface of the eye that contains photoreceptor cells.

Question 7

Photoreceptors

Answer 7

Light sensitive cells (rods and cones) in the eye upon which light registers

Question 8

rods

Answer 8

Photoreceptors that are sensitive only to the intensity of light. ( Shades of light and dark)

Question 9

cones

Answer 9

Photoreceptors that are sensitive to color.

Question 10

Bipolar cells

Answer 10

A layer of interconnecting cells in the eye that connect photoreceptors to ganglion cells.

Question 11

Ganglion cells

Answer 11

Nerve cells in the back of the eye that transmit neural impulses in response to light stimulation, the axons which make up the optic nerve.

Question 12

Optic nerve

Answer 12

The nerve that carries neural impulses generated by light stimulation from the eye to the brain.

Question 13

Blind spot

Answer 13

The area in the retina where the optic nerve leaves the eye and that contains no photoreceptor cells.

Question 14

Fovea

Answer 14

The area near the center of the retina that contains only cones and that is the center of focus for clearest vision.

Question 15

Feature detectors

Answer 15

Specialized neurons inn the visual cortex that respond only to particular features of visual stimuli, such as horizontal or vertical lines.

Question 16

trichromatic theory

Answer 16

A theory of color vision that posits that the ability to see different colors depends on the relative activity of three types of color receptors in the eye (red, green, and blue violet.

Question 17

Afterimage

Answer 17

The visual image of a stimulus that remains after the stimulus is removed.

Question 18

Trichromats

Answer 18

People with normal color vision who can discern all the colors of the visual spectrum

Question 19

Monochromats

Answer 19

People who have no color vision and can see only in black and white

Question 20

Dichromats

Answer 20

People who can see some colors but not others.