The Eye

Question 1

What is the SCLERA?

Answer 1

The tough, supporting wall of eye

Question 2

What is the CORNEA?

Answer 2

The transparent outer layer found at the front of the eye. It refracts and bends the light

Question 3

What is the IRIS?

Answer 3

Contains the muscles that allow it o control the diameter of the pupil and therefore how much light enters the eye

Question 4

What does the LENS do ?

Answer 4

focuses the light on to the RETINA

Question 5

What does the retina contain?

Answer 5

Receptor cells sensitive to light intensity and colour

Question 6

What controls the shape of the lens?

Answer 6

CILIARY MUSCLES and SUSPENSORY LIGAMENTS

Question 7

What does the OPTIC NERVE do ??

Answer 7

Carries impulses from receptors on the retina to the brain

Question 8

What’s a reflex in the eye ?

Answer 8

• The pupil is made smaller in bright light, so the amount of light let it is reduced
• the pupil is made bigger in dim light to increase the amount of light

Question 9

What can damage the RETINA ?

Answer 9

Bright light

Question 10

What is accommodation??

Answer 10

When the eye focuses light on the retina by changing shape of the lens

Question 11

What controls the size of the pupil?

Answer 11

• The circular muscles in the IRIS

* radial muscles

Question 12

How does the eye focus on near objects?

Answer 12

The ciliary muscles contract

Which slackens the suspensory ligaments

The lens becomes fat

This increased the amount of light it refracts

Question 13

How does the eye focus on distant objects ?

Answer 13

The ciliary muscles relax

Which allows the suspensory libaments to pull tight

This makes the lens go thin

So it refract light by a smaller amount

Question 14

Why re people long sited ?

Answer 14

• The lens is the wrong shape and doesn’t refract the light enough
• The eye ball is too short

Question 15

Why are people short sited?

Answer 15

• the lens is the wrong shape and refracts the light too much
• the eyeball is too long

Question 16

What lens is used for longsightedness people?

Answer 16

Convex

Lens that curves outwards

Question 17

What lens is used for short sided people ?

Answer 17

Concave

A lens that curves inwards

Question 18

What are convex lenses used for ? And what do they do ?

Answer 18

Longsired people

Increase refraction

Question 19

What are concave lenses used for? And what do they do ?

Answer 19

Short sited people

Reduce refraction

Question 20

Give the treatments for vision defects

Answer 20

• contact lenses
• laser eye surgery
• replacement lens surgery

Question 21

Advantages of contact lenses

Answer 21

• lightweight
• invisible
• convenient for sports

Question 22

What is the name given to the transparent layer at the front on the eye?

Answer 22

Cornea

Question 23

What is the scientific word for short sited people ?

Answer 23

Myopia

Question 24

What is the scientific term for Long sited people?

Answer 24

Hyperopia

Question 25

Explain the cause of shortsightedness

Answer 25

The lens is the wrong shape

Reflects the light too much

Eyeball is too long

Question 26

Describe the function of th iris

Answer 26

Control the diameter of the eye

The amount of light entering the eye

Question 27

Describe how information about light entering the eye is passed to the brain

Answer 27

Information is sent in impulses

Via the Optic nerve