Unit 2: Visual field defects, double vision & optic disc swelling
1: Visual Field Defects
Visual Pathway
Reproduced from Practical Neurology, S A Cooper, R A Metcalfe, volume 9, 324-334, Dec 1 2009. BMJ Publishing Group Ltd
- Nerve fibres from each retina leave the eye at the optic disc and travel along the optic nerve.
- The optic nerves of the two eyes join at the optic chiasm.
- Nerve fibres from the nasal retina of each eye cross over at the chiasm and travel down the contralateral optic tract.
- Nerve fibres from the temporal retina do not cross over at the chiasm and therefore travel down the ipsilateral optic tract.
- The optic tracts connect with the lateral geniculate body. At this point synapses are formed with neurones passing through the optic radiations to reach the visual cortex.