Parts of the eye

Question 1

Cornea

Answer 1

Tough, transparent layer at front of eye. Allows light to enter and begins to bring it to a focus.

Question 2

Iris

Answer 2

Coloured part containing muscles which alter diameter of pupil and control amount of light entering eye.

Question 3

Pupil

Answer 3

Opening surrounded by iris. Allows light to enter eye. Iris muscles enlarge pupil size in dim light to allow light in, and limit light in bright light, thus preventing damage to retina.

Question 4

Lens

Answer 4

Flexible transparent biconvex structure. Focuses light on to retina.

Question 5

Retina

Answer 5

Light-sensitive layer containing two types of receptor cell: rods (sensitive to dim light) and cones (sensitive to bright light and colour)

Question 6

Blind spot

Answer 6

Point where receptors are absent and fibres from retina enter optic nerve.

Question 7

Optic nerve

Answer 7

Carries nerve impulses from retina to brain.