the eye

Question 1

what is the retina

Answer 1

it lies at the back of the eye and contains rods and cones and turns light into electrical signals

Question 2

what are rods and cones

Answer 2

nerve cells that are sensitive to light

Question 3

what is the optic nerve

Answer 3

a fibre that connects the eye to the brain

Question 4

what happens so you can see

Answer 4

1. light enters the eye
2. the right amount of light needs to enter
3. an image needs to be focused on the retina
4. light needs to be converted to nerve impulses

Question 5

how to form an image on the retina

Answer 5

refraction is done by the lens and changing the shape of the lens alters the amount of bending

Question 6

how does vision work

Answer 6

the lens focus on different objects at different distances by changing focal lengths

Question 7

what happens to the lens when seeing far away

Answer 7

the lens stretch and become flat because of contracted muscles

Question 8

what happens to the lens when seeing near

Answer 8

the lens become fat because of the relaxed muscles

Question 9

what colour to rods see

Answer 9

black and white

Question 10

what colours do cones see

Answer 10

either red, green or blue