human eye

Question 1

cornea

Answer 1

provide most of refraction

Question 2

lens

Answer 2

converges light at retina

Question 2

iris

Answer 2

control size of pupil
determines the color of eye

Question 3

pupil

Answer 3

window of eye
control amt. of light entering eye

Question 4

retina

Answer 4

delicate membrane having light sensitive cells

Question 5

ciliary muscles

Answer 5

hold lens in position
modify the curvature of lens

Question 6

optic nerve

Answer 6

transmit visual info. from retina to brain

Question 7

aqueous humus

Answer 7

liquid between cornea and eye lens

Question 8

vitreous humus

Answer 8

liquid between lens and retina

Question 9

far point of eye

Answer 9

infinite

Question 10

near point of eye

Answer 10

25 cm

Question 11

power of accomodation

Answer 11

changing focal length of eye by cilliary muscle

Question 12

to see a far object

Answer 12

muscles - relaxed
lens - thin
f - increas

Question 13

to see a near object

Answer 13

muscle - contract
lens - thick
f - decrese

Question 14

myopia(near sightedness)
its causes
correction

Answer 14

far object cant be seen clearly
image is formed in front of retina

causes:
-excessive curvature of eye lens
-stretching of lens

correction- concave lens

Question 15

hypermetropia (far sightedness)
its causes
correction

Answer 15

near object cant be seen clearly
image is formed behind retina

causes
-focal length of eye become too long
-eyeball becomes too small

correction-convex lens

Question 16

highest wavelength

Answer 16

red

Question 17

lowest wavelength

Answer 17

violet

Question 18

we see rainbow in which direction
-opposite direction of sun
-same direction of sun

Answer 18

opposite