Ocular Motility and Stereopsis

Question 1

Name the 6 EOMs.

Answer 1

Question 2

What are the actions of the superior oblique?

Answer 2

Superior oblique– used for reading (down and in– conversion with reading)

Question 3

What are the actions of the inferior oblique?

Answer 3

– When looking nasally– moves eye up

– When looking straight ahead– extorts

Question 4

What is the innervation of the 6 EOMs?

Answer 4

SO4 LR6 (III)

Question 5

What EOMs are yoked?

Answer 5

SO-IR

Question 6

If there is abnormal ocular motility, where is the lesion?

Answer 6

Muscle (agonist or antagonist)

Nerve

Brain

Question 7

Define strabismus.

Answer 7

Misalignment/deviation

“Squint”

“Lazy eye”

Question 8

Define ortho-.

Answer 8

No measurable deviation

Question 9

Define hetero-.

Answer 9

Measurable deviation (direction not specified)

Question 10

Define phoria.

Answer 10

Deviation that is nomally under full control, comes out when fusion is disrupted (i.e. during cover/uncover test)

Question 11

Define fusion.

Answer 11

Each eye sends slightly different images but brain fuses them to be one good image.

Question 12

Define tropia.

Answer 12

Constant deviation that is not controlled. Fusion cannot occur, pt has diplopia but the brain blocks/supresses the second image.

Question 13

Define eso-.

Answer 13

inward/nasal deviation

Question 14

Define exo-.

Answer 14

Outward/temporal deviation.

Question 15

Define hyper-.

Answer 15

Upward deviation.

Question 16

Define hypo-.

Answer 16

Downward deviation.

Question 17

Define duction.

Answer 17

Movement of a single eye.

Question 18

Define version.

Answer 18

Conjugate eye movements.

Question 19

Define vergence.

Answer 19

Eyes move in opposite directions.

Example– convergence when reading.

Question 20

Define microtropia/microfixation syndrome.

Answer 20

• Small deviation (<8PD)
• Slightly unequal vision
• Suppression of central vision in worse eye
• Abnormal depth perception on OVT (can be intermittent)

Question 21

What is the aeromedical significance of phorias and tropias?

Answer 21

They can become manifest under physiological stress.

Question 22

Of near or distance testing for ocular misalignment, which is more important? Why?

Answer 22

Distance. Formations are flown at distance, not 14 inches.

Question 23

What three tests should the FSO do for ocular motility?

Answer 23

• OVT (visual acuity, phoria, steropsis)
• Motility
• Cover/uncover test

Question 24

If person fails OVT but passes AO vectograph, do they need a waiver?

Answer 24

Yes

Question 25

Define scanner duty restriction.

Answer 25

no tasking to visually clear the aircraft from other aircraft or objects in the air or on the ground within 200 meters

Question 26

How many types of depth perception are there? Name them.

Answer 26

2– monocular and binocular

Question 27

List the three aspects of depth perception.

Answer 27

1. Spatial localization
2. Orietation of self in environment
3. Localize object in relation to self or other object

Question 28

Name 5 tasks that pilots require depth perception for.

Answer 28

1. Taxiing/parking
2. Landing
3. Formations
4. Low level flying
5. Aerial refueling

Question 29

Name 5 visual cues for monocular depth perception.

Question 30

Define motion parallax

Answer 30

Rocks, fence posts that are close look like they are moving by fast, whereas ones across street look like going by slower

Question 31

Define aerial perspective

Answer 31

Objects closer appear higher contrast level than objects at distance

Question 32

Define illumination perspective

Answer 32

Shadows aid in detecting depth (i.e. crater perspective)

Question 33

If pt fails OVT-DP, what is the first dtep that should be taken?

Answer 33

Check glasses/visual acuity

Question 34

What aircrew positions need to pass OVT-DP?

Answer 34

Pilots, navigators, scanners

Question 35

What is the standard arc sec that must be passed?

Answer 35

60 arc seconds (which is what the AO vectograph is)

Question 36

Name the 6 EOMs.

Answer 36