Eyes (triple only)

Question 1

Name the process used to focus light from near and far objects

Answer 1

Accommodation

Question 2

What stimuli are the receptors of the eye sensitive to?

Answer 2

Light intensity
Colour (wavelength of light)

Question 3

Whihc part of the eye is responsible for changing the amount

of light entering the eye?

Answer 3

Iris

Question 4

Identify the conditions present in diagram A and B

Answer 4

A = Bright light

B = Dim light

Question 5

The lens can change shape to focus light from near and far objects.

What is the name of this process?

Answer 5

Accommodation

Question 6

Describe the structure and function of the retina

Answer 6

Found at the back of the eye
Contain light sensitive cells (rods and cones)
Light sensitive cells send impulses to the brain

Question 7

Name the part of the eye labelled 1

Answer 7

Cornea

Question 8

Name the part of the eye labelled 2

Answer 8

Pupil

Question 9

Name the part of the eye labelled 3

Answer 9

Iris

Question 10

Name the part of the eye labelled 4

Answer 10

Lens

Question 11

Name the part of the eye labelled 5

Answer 11

Retina

Question 12

Name the part of the eye labelled 6

Answer 12

Ciliary muscle

Question 13

Name the part of the eye labelled 7

Answer 13

Optic nerve

Question 14

Describe the structure and function of the optic nerve

Answer 14

Optic nerve connects the eye and the brain
Contains sensory neurones
Send electrical impulses from the retina to the brain

Question 15

Describe the structure and function of the sclera

Answer 15

Tough outer layer of the eye
Protects internal structures

Question 16

Describe the structure and function of the cornea

Answer 16

Curved transparent layer at the front of the eye
Lets light into the eye
Allows light to be focussed on the retina

Question 17

Describe the structure and function of the iris

Answer 17

Iris is a muscle
Controls the size of the pupil by contracting and relaxing the muscles
Allows the eye to adjust to bright and dim light

Question 18

Describe the structure and function of the ciliary muscles and

suspensory ligaments

Answer 18

Hold the lens in place
Can change the shape of the lens

Question 19

Describe how the iris alters the size of the pupil in bright ight

Answer 19

Circular muscles contract
Radial muscles relax
Makes pupil smaller so less light can enter the eye

Question 20

Describe how the iris alters the size of the pupil in dim light

Answer 20

Circular muscles relax
Radial muscles contract
Makes pupil larger so more light can enter the eye

Question 21

Describe how the eye changes the shape of the lens when focussing on near objects

Answer 21

Ciliary muscle contract
Suspensory ligaments loosen
Lens becomes thicker and more curved
Light is refracted strongly
Image forms on the retina

Question 22

How does the eye focus on distant objects?

Answer 22

Ciliary muscles relax
Suspensory ligaments tighten
Lens is puller thinner
Light is refracted less strongly
Image falls on the retina

Question 23

What condition does this person suffer from?

Answer 23

Short sighted

Myopia

Question 24

What is myopia?

Answer 24

Short-sightedness
Lens becomes too curved
Light is focused in front of the retina
Images appear blurry

Question 25

How can myopia be treated?

Answer 25

Using glasses or contact lenses Concave lens Spreads the light so they can be focused on the retina

Question 26

Name the condition this person suffers from

Answer 26

Long sightedness Hyperopia

Question 27

What is hyperopia?

Answer 27

Long-sightedness Lens is too flat Light is focused behind the retina Images appear blurry

Question 28

How can hyperopia be treated?

Answer 28

Using glasses or contact lenses Convex lens Brings light rays together Image formed on the retina

Question 29

What is laser eye surgery?

Answer 29

Use lasers to fix visual defects n adults Myopia - laser reduces the thickened of the cornea so light is refracted less strongly Hyperopia - laser alters curvature of the cornea so light is refracted correctly

Question 30

How can replacement lenses by used to treat visual defects?

Answer 30

Replacement lens replaces the natural lens

Question 31

What are the risks of lens replacement?

Answer 31

Can cause retinal damage, cataracts and infections