The Eye

Question 1

Function of cornea?

Answer 1

Convex and transparent so refracts light as it enters.

Question 2

Function of iris?

Answer 2

Controls how much light enters pupil.

Question 3

Function of lens?

Answer 3

Focuses light onto the retina.

Question 4

Function of retina?

Answer 4

Contains the light receptors: rods and cones.

Question 5

Job of rod cells?

Answer 5

Responsible for detecting light and dark.

Question 6

What do rod cells contain and what happens to it when light is shone on it?

Answer 6

Contain pigments called rhodopsin, which when light shines on it, it breaks down into two proteins; retinal and opsin in a process called bleaching.

Question 7

Job of cone cells?

Answer 7

Responsible for colour vision.

Question 8

What do cone cells contain?

Answer 8

Contain pigment called iodopsin; 3 different types each sensitive to either red, green or blue wavelengths.

Question 9

Which sight length is corrected by which type of lens?`

Answer 9

Short sighted - Concave

Long sighted - convex

Question 10

How do eyes focus on objects at near point?

Answer 10

When ciliary muscles contract, they shorten and squeeze the lens, making it thicker.

Question 11

How do eyes focus on far objects?

Answer 11

When ciliary muscles relax, they lengthen and stretch lens, making it thinner.