The brain and eyes

Question 1

Cornea

Answer 1

Transparent bit in front of the pupil
Starts focusing of light rays

Question 2

Pupil

Answer 2

A hole in the middle of the iris
Where light passes through

Question 3

Iris

Answer 3

Controls size of the pupil
Because the pupil is a hole in the middle of it

Question 4

Lens

Answer 4

Big blob behind the iris and pupil
Light travels from pupil to lens
It focuses the light rays to the back of the eye

Question 5

Retina

Answer 5

Back of the eye where light is focused to
Contains receptor cells for detection of light intensity and colours

Question 6

Optic nerve

Answer 6

Once Retina receptor cells detect the light
It sends electrical impulses to the brain to

Question 7

Sclera

Answer 7

White part on outer layer to protect the eye

Question 8

Ciliary muscles and Suspensory ligaments

Answer 8

Changes shape of the lens to focus on long and short distances

Question 9

How does the eye focus on different distances?

Answer 9

By a process called accommodation
Controlled by suspensory ligaments and ciliary muscles
That control the shape of the lens

Question 10

What does accommodation include?

Answer 10

Ciliary muscles and suspensory ligaments

Question 11

How does the eye focus on far objects?

Answer 11

Ciliary muscle (circle) relaxes and thus expands
So the suspensory ligaments contracts thus tighten and pulled tight
So the lens is pulled thin and only focuses light a tiny bit
But because long distant objects only require small amount of focusing so they refract to the retina

Question 12

How does the eye focus on close objects?

Answer 12

Ciliary muscle contracts and pulls in
So the suspensory ligaments relax and loosen
Thus the lens are thicker and can focus light stronger
Closer objects require more focusing so it can now focus it to a point in the retina

Question 13

Hyperopia

Answer 13

Long sightedness
Because eyeball is too short or lens less elastic
So light rays in short distance objects not focused enough and so behind the retina

Question 14

How to fix hyperopia?

Answer 14

Glasses with CONVEX lens
Because they partially focus light before entering the eye

Question 15

Myopia

Answer 15

Short sightedness
Can’t focus on long distant objects
Because light focuses before it reaches the retina
If the lens is too thick or eyeball is too fat

Question 16

How to fix myopia?

Answer 16

Use concave lens
Because it partially un focuses the rays before it enters the eye so it can focus at the retina
Not before

Question 17

Laser eye treatment

Answer 17

Changes lens shape
So it can refract light more or less

Question 18

How does the eye focus in different light intensities?

Answer 18

By changing shape of the iris and pupil

Question 19

Does adapting to light intensities include accommodation?

Answer 19

NO
DOESNT INCLUDE CILIARY MUSCLES OR SUSPENSORY LIGAMENTS

Question 20

How eye focuses if it’s too dark

Answer 20

Change in intensity detected by light receptors in retina
Sends electrical signals down optic nerve to the brain
Sends impulses to the iris
So it contracts, pupils are now larger and can have more light enter

Question 21

How eye focuses if it’s to bright

Answer 21

Change in intensity detected by light receptors in retina
Sends electrical signals down optic nerve to the brain
Sends impulses to the iris
So it relaxes and pupils are smaller so less light enters