The iris reflex - Eye Flashcards
What is the danger of bright light
damage to retina
What does the iris reflex control
the size of your pupil
What happens to pupil size in bright light conditions and WHY
+What is the name of the pupil now
Decrease in size to let less light in and prevent damage
constricted pupil
What happens to pupil size in low light conditions and WHY
+ What is the name of the pupil now
increase in size to let more light in so we get more image of surroundings
Dilated pupil
What is the iris made up of to control size of pupil
it has two muscles called
circular muscles closest to pupil
radial muscles which are straight and on the outside
What happens to muscles when there is bright light
so the pupil needs to get smaller
therefore circular muscles contract to push pupil size down
and radial muscles relax
What happens to muscles when there is low light
so pupil needs to get bigger
therefore circular muscles relax and
radial muscles contract and pull outwards to increase pupil size
