eye

Question 1

what happens to eye in bright light

Answer 1

-circular contract
-radial relax
-iris disc gets larger
-pupil constricts

-remember bright = CC and RR, and dim must be the opposite

Question 2

what happens to eye in dim light

Answer 2

-circular relax
-radial contract
-iris disc gets smaller
-pupil dilated

Question 3

what happens to eye focusing on distant object

Answer 3

-ciliary muscles relax
-suspensory ligaments tighten
-lens pulled thin and has a less convex/flatter shape
-meaning less refraction of light

-remember it like this: if you have a test distant in the future, you can relax, just like your ciliary muscles
-also remember people look smaller (thinner) from far away, so your lens becomes thinner

Question 4

what happens to eye focusing on close objects

Answer 4

-ciliary muscles contract
-suspensory ligaments slacken
-lens not pulled tight so widens and more convex shape
-meaning more refraction of light

Question 5

which nerve which impulses to brain from eye

Answer 5

• Optic nerve

Question 6

What is Iris/what does it do

Answer 6

• Ring of muscles with hole in the middle (Pupil)
• Controls the amount of light allowed to enter eye

Question 7

What is the retina/ what does it do

Answer 7

• Layer of light sensitive cells called rods and cones
• captures light and helps translate it into images you see

Question 8

what is the cornea/function

Answer 8

• Curved transparent disc at front of eye
• does most of focusing

Question 9

What is pupil/ function

Answer 9

• Circular opening whose size is controlled by iris
• allows light to enter the eye (controlled by iris)

Question 10

What is lens/ function

Answer 10

• soft, flexible and transparent
• shape can be changed to fine tune focusing of light in the retina

Question 11

What are the Ciliary muscles/function

Answer 11

• A ring of muscle at edge of eye which circles the lens
• Contracts and relaxes to thicken/thin the lens

Question 12

What are suspensory ligaments/ function

Answer 12

• Strong fibres
• Attach ciliary muscles to lens

Question 13

what is the optic nerve/what does it do

Answer 13

• consists of many neurones which carry impulses from retina to brain

Question 14

What is fovea

Answer 14

• Region of retina with greater density of rods and cones

Question 15

What is conjunctiva/ function

Answer 15

• a Mucous membrane
• covers the eye to prevent infection

Question 16

what does the eye look like when focussing on a nearby object

Answer 16

Question 17

what does the eye look like when focussing on a distant object

Answer 17