Case 3 - Visual Pathway and Defects Flashcards
how many rods are there
around 100 million
what do rods allow for
vision in low lighting conditions, peripheral vision and lower resolution
how many cones are there
around 6 million
what do cones allow for
detailed vision, colour vision and brighter light
what is the fovea made of
cones only
how do the ganglion cells transmit light signals out of the eye
as a series of impluses
what are the four subcortical regions of the brain that the retina projects to
- lateral geniculate nucleus
- superior colliculus
- hypothalamus
- pretectum
what is the primary visual pathway
the lateral geniculate nucleus - image forming Vision
what are the secondary visual pathway s
hypothalamus and pretectum
where does the optic disc go from
the nasal to fovea
where is the blind spot
in temporal visual field at about 15 degrees eccentricity
why do you get macular sparing
because the visual cortex is so large and it has two blood supplies
if you get superior visual field loss what is affected
optic radiations in Meyer’s loop (temporal lobe) affected
what is affected in inferior visual field loss
optic radiations in parietal lobe affected
