The Eye

Question 1

Function of the cornea

Answer 1

To focus light

Question 2

What is the cornea?

Answer 2

A curved transparent disc at the front of the eye

Question 3

Function of the pupil

Answer 3

Hole to allow light through to the retina. Controls how much light enters the eye.

Question 4

What is the pupi

Answer 4

A circular opening whose size is controlled by the iris

Question 5

What is the iris

Answer 5

A ring of muscles around the pupil

Question 6

Function of the iris

Answer 6

To control the size of the pupil and the amount of light that can enter the eye.

Question 7

What is the lens

Answer 7

A soft flexible transparent part of the eye behind the pupil

Question 8

Function of the lens

Answer 8

Changes shape to fine tune where light is focused on the retina

Question 9

What are the ciliary muscles

Answer 9

A ring of muscle which circles the lens

Question 10

What is the function if the ciliary muscles

Answer 10

To control the size/ shape of the lens. When the ciliary muscles contact the lens gets fatter, when they relax, the lens gets thinner.

Question 11

What are the suspensory ligaments

Answer 11

Strong fibres which attach the lens to the ciliary muscles

Question 12

Function of the ciliary muscles

Answer 12

To control the shape of the lens to focus light ton the retina

Question 13

What is the retina

Answer 13

The back part of the eye containing rod and cone cells.
Rod cells: sensitive to light intensity. Allows to see in very dim light
Cone cells: detect colour

Question 14

Function of the retina

Answer 14

To detect light and colour

Question 15

What is the optic nerve

Answer 15

A nerve leaving the eye and consists of neurones to carry impulses to the brain

Question 16

Function of the optic nerve

Answer 16

To carry impulses to the brain

Question 17

What is the fovea

Answer 17

The region bof the retina with the greatest number of cones.

Question 18

What is the conjunctiva

Answer 18

A mucous membrane that covers the eye

Question 19

Function of the conjunctiva

Answer 19

To prevent infection

Question 20

What happens to the eye when focusing on a near object?

Answer 20

When near, ciliary muscles contract, suspensory ligaments loosen, lens becomes thicker and more convex so light rays are refracted more strongly

Question 21

What happens to the eye when focussing on a far object?

Answer 21

Ciliary muscles relax, suspensory ligaments tighten, lens becomes thin and less convex so light rays are refracted less strongly.

Question 22

What happens to the eye when exposed to bright light

Answer 22

Circular muscles contract, radial muscles relax making the iris wider and the pupil smaller.

Question 23

What happens to the eye in dim light

Answer 23

Radial muscles contract, circular muscles relax making the iris narrower and the pupil dilated.

Question 24

describe the structure of the cornea

Answer 24

Cornea: a curved transparent disc at the front of the eye. Focuses light.

Question 25

describe the structure of the pupil

Answer 25

Pupil: a circular opening whose size is controlled by the iris (the coloured part of the eye)

Question 26

describe the structure of the iris

Answer 26

iris: a ring of muscles with a hole in the middle (pupil). The iris controls how much light can enter the eye.

Question 27

describe the structure of the lens

Answer 27

Lens: this is soft, flexible and transparent. It’s shape can be changed to fine tune the focussing of light onto the retina.

Question 28

describe the structure of the cellar muscles

Answer 28

Ciliary muscles: a ring of muscle at the edge of the eye which circles the lens. When it contracts the lens gets fatter. When it relaxes, the lens gets thinner.

Question 29

describe the structure of the suspensory ligaments

Answer 29

Suspensory Ligaments: strong fibres which attach the lens to the ciliary muscles.

Question 30

describe the structure of the retina

Answer 30

Retina: contains light sensitive cells named rods and cones.

Question 31

describe the structure of the optic nerve

Answer 31

Optic nerve: consists of many neurones which carry impulses from the retina to the brain.

Question 32

describe the structure of the fovea

Answer 32

Fovea: the region of the retina with the greatest number of cone cells.

Question 33

describe the structure of the conjunctiva

Answer 33

Conjunctiva: a mucous membrane that covers the eye to prevent infection.

Question 34

describe the structure of the sclera

Answer 34

Sclera: outer white part if the eye.