Versions and Vergences Flashcards
Infranuclear Controls
CN 3, 5, 6 and their muscles
Nuclear Controls
Cranial nuclei
Supranuclear Contros
higher order; plans and controls eye movement
cortex, cerebellum, brainstem
Versions and Vergences are controlled by….
supranuclear pathway
Saccades
FAST conjugate eye movement for refixation/
moves fovea to object of interest
voluntary, some can be reflex
Saccade- Version or Vergence?
Version
Saccade Latency
time between stimulus and response
120- 200ms
Saccades develop by age…
1
Pursuits
maintains fovea focus on a slowly moving target
matches eye velocity to target velocity
voluntary
Pursuit Latency
shorter than saccades- faster start
125ms
Pursuits develop by…..
3-4 months
Vestibulo-ocular Reflex
VOR
stabilize retinal image during brief head movements
seen in doll’s head maneuver
does not require stimuli
VOR is developed by….
Horizontal- at birth
Vertical- later
Vestibular damage results in….
horizontal nystagmus
Dolls Head Maneuver
eyes move opposite to head turn