Eye Structure and Function

Question 1

what is the eye?

Answer 1

a sensory organ which detects light and sends an impulse to the brain which converts that information into an image which is what you see

Question 2

what is the cornea?

Answer 2

a curved transparent disc at the front of the eye - does most of the focusing

Question 3

what is the pupil?

Answer 3

a circular opening whose size is controlled by the iris (the coloured part of the eye)

Question 4

what is the iris?

Answer 4

a ring of muscles with a hole in the middle (pupil) - the iris controls how much light enters the eye

Question 5

what is the lens?

Answer 5

this is soft, flexible and transparent - its shape can be changed to find tune the focusing of light onto the retina

Question 6

what are the ciliary muscles?

Answer 6

a ring of muscle at the edge of the eye which circles the lens - when it contracts the lens gets fatter, when it relaxes the lens gets thinner

Question 7

what are the suspensory muscles?

Answer 7

strong fibres which attach the lens to the ciliary muscle

Question 8

what is the retina?

Answer 8

contains light sensitive cells called rods and cones

Question 9

what is the optic nerve?

Answer 9

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

Question 10

what is the fovea?

Answer 10

the region of the retina with the greatest number of cones

Question 11

what is the conjunctiva?

Answer 11

a mucous membrane that covers the eye to prevent infection