L11: Vision 1 Flashcards
What is accomodation?
When the eye lens is made fatter or thinner to adjust focus
What is spatial frequency?
an important cue that drives auto focus in eyes and cameras
What do extra-ocular muscles do?
control vergence eye movements which line both foveas up.
How do we recieve the info from our eyes?
the brain merges the image form both eyes and can sense binocular disparity to percieve depth
What are rods?
type of photoreceptor cell, help give us good vision is low light
What pigment do rods contain?
rhodopsin
What are cones?
type of photoreceptor cell, give us our colour vision
What happens to our vision cells in the dark?
they depolarise and release neurotransmitter glutamate
What happens to our vision cells in the light?
they hyperpolarise, sodium channels close and less neurotransmitters are released
what does depolarise mean?
reduction in the electric potential across membrane
What does hyperpolarise mean?
increase in the electric potential acorss the membrane
What kind of potentials (apart from ganglion cells) do all retina celll types use?
graded potentials
What do ganglion cells do?
final output of the retina
What do photoreceptors (rods and cones) do?
transduce light into electro-chemical signals
What do bipolar cells do?
link photoreceptors with ganglion cells and can be on/off
