Lecture 2- Vision

Question 1

what is light?

Answer 1

a source of electromagnetic radiation (sun) emits a series of photons (smallest possible unit of energy) which travel through the vacuum of space as a wave

Question 2

Photon

Answer 2

energy released through the shift in orbits of electrons

Question 3

wavelength

Answer 3

distance between the crests of the wave (perceived as different colours)

Question 4

amplitude

Answer 4

the height of the wave (perceived as differences in brightness)

Question 5

refraction

Answer 5

occurs when light is forced to change course because it has passed through a dense, but not opaque, medium

Question 6

Sclera

Answer 6

“white bit”: filled with fluids that maintain eye shape. attached to muscles that move the eye

Question 7

iris

Answer 7

coloured part, connects to sphincter muscles that contract in order to control the size of your “pupil”

Question 8

pupil

Answer 8

hole in your eye that lets light in

Question 9

cornea

Answer 9

clear membrane that attaches to the sclera and bulges out slightly

Question 10

anterior chamber

Answer 10

fluid-filled space behind the cornea

Question 11

aqueous humor

Answer 11

fluid behind cornea

Question 12

lens

Answer 12

refracts light onto an area at the back of the eye called the “retina”; lens can change shape

Question 13

ciliary muscle

Answer 13

attached to lens by the zonules of zinn

Question 14

myopia

Answer 14

-nearsightedness
- occurs when a lens doesn’t become thin, can be caused by misshapen eyeball

Question 15

hyperopia

Answer 15

-farsightedness
- lens wont thicken, nearby objects become hard to see

Question 16

vitreous chamber

Answer 16

behind lens, light passes through, filled with transparent “vitreous fluid”

Question 17

retina

Answer 17

spread across back of eyeball
- 3 main parts: pigment epithelium, photo receptors, neurons

Question 18

pigment epithelium (retina)

Answer 18

absorbs scattered light, serves to protect and nourish the cells retina

Question 19

photo receptors (retina)

Answer 19

1. rods- brightness
2. cones - colour

Question 20

rhodopsin

Answer 20

interact with photons to begin a process that ends with opening of cation channels in rods and cones

Question 21

rods

Answer 21

• dim light vision
• responds to wave amplitudes
• only 1 type

Question 22

cones

Answer 22

• colour vision
• respond to wavelengths
• 3 types (mostly) (RGB)

Question 23

outer segment of photoreceptor

Answer 23

stores photopigment molecules which absorb light and start the process of transduction

Question 24

inner segment (photoreceptor)

Answer 24

contains the structure which generates the photopigment molecules

Question 25

trichromacy theory

Answer 25

we have 3 types of cones, sensitive to red, green, blue (RGB scale)