Ocular Motility and Stereopsis Flashcards
Name the 6 EOMs.
What are the actions of the superior oblique?
Superior oblique– used for reading (down and in– conversion with reading)
What are the actions of the inferior oblique?
– When looking nasally– moves eye up
– When looking straight ahead– extorts
What is the innervation of the 6 EOMs?
SO4 LR6 (III)
What EOMs are yoked?
SO-IR
If there is abnormal ocular motility, where is the lesion?
Muscle (agonist or antagonist)
Nerve
Brain
Define strabismus.
Misalignment/deviation
“Squint”
“Lazy eye”
Define ortho-.
No measurable deviation
Define hetero-.
Measurable deviation (direction not specified)
Define phoria.
Deviation that is nomally under full control, comes out when fusion is disrupted (i.e. during cover/uncover test)
Define fusion.
Each eye sends slightly different images but brain fuses them to be one good image.
Define tropia.
Constant deviation that is not controlled. Fusion cannot occur, pt has diplopia but the brain blocks/supresses the second image.
Define eso-.
inward/nasal deviation
Define exo-.
Outward/temporal deviation.
Define hyper-.
Upward deviation.
Define hypo-.
Downward deviation.
Define duction.
Movement of a single eye.
Define version.
Conjugate eye movements.
Define vergence.
Eyes move in opposite directions.
Example– convergence when reading.
Define microtropia/microfixation syndrome.
- Small deviation (<8PD)
- Slightly unequal vision
- Suppression of central vision in worse eye
- Abnormal depth perception on OVT (can be intermittent)
What is the aeromedical significance of phorias and tropias?
They can become manifest under physiological stress.
Of near or distance testing for ocular misalignment, which is more important? Why?
Distance. Formations are flown at distance, not 14 inches.
What three tests should the FSO do for ocular motility?
- OVT (visual acuity, phoria, steropsis)
- Motility
- Cover/uncover test
If person fails OVT but passes AO vectograph, do they need a waiver?
Yes
Define scanner duty restriction.
no tasking to visually clear the aircraft from other aircraft or objects in the air or on the ground within 200 meters
How many types of depth perception are there? Name them.
2– monocular and binocular
List the three aspects of depth perception.
- Spatial localization
- Orietation of self in environment
- Localize object in relation to self or other object
Name 5 tasks that pilots require depth perception for.
- Taxiing/parking
- Landing
- Formations
- Low level flying
- Aerial refueling
Name 5 visual cues for monocular depth perception.
Define motion parallax
Rocks, fence posts that are close look like they are moving by fast, whereas ones across street look like going by slower
Define aerial perspective
Objects closer appear higher contrast level than objects at distance
Define illumination perspective
Shadows aid in detecting depth (i.e. crater perspective)
If pt fails OVT-DP, what is the first dtep that should be taken?
Check glasses/visual acuity
What aircrew positions need to pass OVT-DP?
Pilots, navigators, scanners
What is the standard arc sec that must be passed?
60 arc seconds (which is what the AO vectograph is)
Name the 6 EOMs.
