the eye

Question 1

What type of organ is the eye?

Answer 1

Sense organ

Question 2

Cornea

Answer 2

Refracts light into eye

Question 3

Iris

Answer 3

Controls light entering pupil

Question 4

Cornea

Answer 4

Refracts light, focus’ it onto retina - accommodation

Question 5

Retina

Answer 5

Light sensitive part at back of eye.Covered in receptors - rods and cones

Question 6

Rods

Answer 6

Sensitive to dim light.Can’t see colour

Question 7

Cones

Answer 7

Sensitive to colour.Not good in dim light.

Question 8

Colour blindness

Answer 8

Caused by lack of cone cells

Question 9

Optic nerve

Answer 9

Carries impulses from receptors to brain

Question 10

Lens

Answer 10

Changes shape to focus

Question 11

What happens when you look at distant objects?

Answer 11

Ciliary muscle relaxesSuspensory ligaments pull tightLens thins, light is refracted less

Question 12

What happens when you look at close objects?

Answer 12

Ciliary muscle contractsSuspensory muscle slackensLens fattens and more roundedLight is refracted more

Question 13

Long sighted

Answer 13

Can see long distance, not close upLens doesn’t bend light enough or eyeball too shortImages of near objects focus behind retinaNeed convex lens

Question 14

Short sighted

Answer 14

Me! Can see near objects, not distance.Lens bends light too much, or eyeball too long.Image of distant objects focuses in front of retina.Concave lens needed.

Question 15

Binocular vision

Answer 15

2 eyes working together (humans)Brain compares images from both eyesMore similarities, the further away objectCan judge distance well, but has narrow field of vision