Functions

Question 1

Conjunctiva

Answer 1

Lubricates and protects tissues at the front of the eye.
Prevents foreign bodies entering the eye orbit.

Question 2

Sclera

Answer 2

Protects the eyeballs against mechanical damage
Allows attachment of eye muscles

Question 3

Cornea

Answer 3

Allows the passage of light while refracting it.

Question 4

Iris

Answer 4

Controls the size of the pupil to adjust the amount of light entering the eye.

Question 5

Pupil

Answer 5

Allows light to enter the eye
Its size can vary

Question 6

Aqueous humour

Answer 6

Maintains the shape of the front chamber of the eye.

Question 7

Lens

Answer 7

Changes shape to adjust the focusing of light onto the retina.

Question 8

Ciliary body

Answer 8

Contraction or relaxation of the circular muscle controls the shape of the lens

Question 9

Suspensory ligaments

Answer 9

Transfers tension in the wall of the eyeball to the lens to make the lens thinner

Question 10

Vitreous humour

Answer 10

Maintains the shape of the rear part of the eyeball and supports the lens.

Question 11

Retina

Answer 11

The light-sensitive cells (rods and cones) initiate impulses in associated neurones when appropriately stimulated.

Question 12

Fovea

Answer 12

A region with high visual acuity that allows colour vision.

Question 13

Choroid

Answer 13

Contains blood vessels which supply the retina
Prevents reflection of light within the eyeball

Question 14

Optic nerve

Answer 14

Transmits impulses from the retina to the optic centre at the back of the brain

Question 15

Blind spot

Answer 15

A region which, if light strikes it, is not sensitive to light.