Vision 2 - visual pathway Flashcards
What is the visual field?
everything you see with one eye - including the periphery
2 ways in which you can test the visual field?
confrontation test and automated perimetry
What is automated perimetry used for?
when there is a disease process to figure out the visual field
How are images of objects in the visual field formed on the retina eg upside down, normal, inverted, narrower etc
inverted and upside down
What fibres cross over at the optic chiasm?
nasal
What is the first part of the pathway to contain fibres solely from the opposite visual field?
optic tract
Where does the optic tract end?
LGB - lateral geniculate body
Where is the LGB found?
in the thalamus
After the LGB what are the fibres called?
optic radiation
What part of the brain is the primary visual cortex?
occipital lobe
Some examples of why the right optic nerve would be damaged
MS, giant cell arthritis, tumour
What happens if the right optic nerve is damaged?
blind in the right eye
Why could the optic chiasm be disrupted?
pituitary tumour
What visual field loss does the disrupted optic chiasm lead to? why?
bitemporal hemianopia
nasal fibres affected - these see the temporal field
If the right optic tract or radiation is damaged what is the visual field loss?
contralateral homonymous hemanopia
