The Eye ?

Question 1

Describe the purpose of the iris

Answer 1

The iris widens and narrows itself to control the amount of light it lets into the eye

Question 2

Describe the purpose of the lens

Answer 2

The lens thicken and thins itself to help focus the light

Question 3

What is the purpose of the vitreous humour

Answer 3

It holds the shape of the eye

Question 4

What is the retina

Answer 4

The layer of cells that detect light at the back of the eye

Question 5

What happens when there is too much light in the eye

Answer 5

The circular muscles of the iris contract making a small pupil

Question 6

What happens when there is little light in the eye

Answer 6

The radial muscles of the iris contract and the pupil is larger

Question 7

What happens to the lens
A) when your viewing objects far away
B) when you are viewing objects close up

Answer 7

A) The lens is long and thin as the light is bent less , the ciliary muscles relax
B) light rays from close objects require more refraction for focusing . The ciliary muscles contract and the lens short and fat

Question 8

Describe the structure of the eye

Answer 8

On the outside you have the cornea
Behind the cornea you have the aqueous humour
Then you have the iris and pupil followed by the lens
Behind the lens you have the vitreous humour
On the inside wall of the eye you have the Retina followed by the choroid and then the optic nerve