The Nervous System- The Eye

Question 1

What does the optic nerve do?

Answer 1

It carries impulses from the receptors to the brain

Question 2

What does the lens do?

Answer 2

It refracts light, focusing it onto the retina

Question 3

What does the sclera do?

Answer 3

It protects the eye

Question 4

What does the retina contain?

Answer 4

The retina contains light receptors and it’s where the light focuses. The receptors are called rods and cones

Question 5

Explain the what happens when light rays pass thought the pupil

Answer 5

When light rays pass through the pupil, the Ray is focused by the lens onto the retina when receptors send impulses along the optic nerve to the brain

Question 6

What is the function of the ciliary muscle?

Answer 6

It contracts and relaxes to change the shape of the lens

Question 7

What does the iris do?

Answer 7

The iris is the coloured part of the eye. The iris controls the size of the pupil and it also controls how much light enters the eye

Question 8

What does the dispensary ligaments do?

Answer 8

Hold the lens in place

Question 9

What does the cornea do?

Answer 9

It focuses light at the back of the eye and it refracts the rays of light

Question 10

What does the pupil do?

Answer 10

The pupil is the hole which light passes. It is controlled by the iris otherwise it will get damaged. When a lot of light passes, it gets smaller and then less light if passing it gets bigger

Question 11

What are rods?

Answer 11

Rods are more sensitive in dim light but can’t sense colour

Question 12

What are cones?

Answer 12

Cones are sensitive to different colours but are not so good in dim light e.g red- green colour blindness

Question 13

Explain what happens to the ciliary muscle when an object is near

Answer 13

It contracts

Question 14

Explain what happens to the ciliary muscle when an object is distant

Answer 14

It relaxes

Question 15

Explain what happens to the suspensory ligaments when an object is near

Answer 15

It’s slackened

Question 16

Explain what happens to the suspensory ligaments when an object is distant

Answer 16

It’s stretched

Question 17

Explain what happens to the muscle tension on lenses when an object is near

Answer 17

The tension in low

Question 18

Explain what happens to the muscle tension in lenses when an object is distant

Answer 18

It’s high

Question 19

Explain what happens to the lens shape when an object is near

Answer 19

It’s fat

Question 20

Explain what happens to the lens shape when an object is distant

Answer 20

It’s thin

Question 21

Explain long sighted

Answer 21

When someone cannot focus on near objects. The lens is the wrong shape and doesn’t bend the light enough or the eyeball is too short. The images of near objects are brought into focus behind the retina. Convex lens can be used to correct it

Question 22

Explain short sighted

Answer 22

When people are unable to focus on distant objects. When lens is the wrong shape and bends the light too much or the eyeball is too long. The images of distant objects are brought into focus in front of the retina m. Concave lens can be used to correct this, alternatively a corneal laser surgery is an option as well.

Question 23

What is binocular vision and what are some of its advantages?

Answer 23

Binocular vision is when both eyes are at the front of the head and they work together. When looking at an object, the brain compares the image seen by each eye. This allows us to judge distance well, but gives us a narrow field of vision

Question 24

What is monocular vision and what are some of its advantages?

Answer 24

Monocular vision is when each eye is at the side of the head and this allows the organism to have a wider field of view

Question 25

Name nine parts of the eye

Answer 25

1. Suspensory Ligaments
2. Cornea
3. Pupil
4. Iris
5. Ciliary Muscle
6. Lens
7. Optic Nerve
8. Retina
9. Sclera