What is the role of vision in flying?
- Provides 80% of spatial orientation cues
- Visual scanning
- Collision avoidance
- Depth & distance perception
- Situational awareness
What threats degrade visual performance in visual aviation?
- Physiological threats (+Gz, fatigue, hypoxia, medical conditions, medications)
- Physical threats (lasers, birdstrike, MDC splatter, wind blast, glare, UV radiation, Ionising radiation, NVGs)
What are the role of cones in focal vision? What’s do they do well? What don’t they do well?
What they do well:
- High visual acuity
- Colour vision
- Fine detail
- High definition
- Object recognition
What’s not so good:
- Needs lots of light
- Night blind spot
- Conscious awareness of gaze
- Small area of visual field
- Hypoxia sensitivity
What is the role of rods in peripheral vision? What do they do well? What don’t they do well?
What they do well:
1) Sensitive in low light
2) Sensitive to movement
3) Horizontal lines
4) Works without conscious awarness
5) Detect peripheral threats
What’s not so good:
1) Low visual acuity
2) Poor colour vision
What are bottom up and top down processing?
- Bottom up is taking sensory information and assembling and integrating it
- Top down processing is using models, ideas and expectations to interpret sensory information
What the physiological limitations of visual performance?
- Focal traps
- Empty field myopia
- Threshold for acuity
- Saccadic vision
- Cues of depth perception
What is saccadic eye movement?
- Rapid flicking movement of eyes
- Blurs retinal image
- Targets may not be perceived
What are the two blind spots?
- Anatomical
- Physiological
What is the proper scan in the aircraft?
- Short regularly spaced eye fixations across the field of vision
- 10 degrees of visual field for about 1 second
What are the visual challenges of high level navs?
1) Empty field myopia
2) Horizon illusions
3) Glare
4) Different illumination cues
