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| Difficulty in noticing colliding air traffic with low contrast level against a featureless background. (image embedded from [http://www.skybrary.aero/images/Low_contrast_acft.jpg] on 7 September 2010) |
Introduction
- A physiological case whereby the human eyes do not receive sufficient image stimulation to be in an actively alert state.
- The human eyes fail to sustain a distant focus of the object due to a low degree of contrast against a featureless background.
- A pair of healthy human eyes can momentarily become near-sighted.
Safety Risks
- Pilots’ Inability to visually notice the existence of traffic, obstacle or terrain.
Possible Situations of Occurrence during Flights
- When the sky is cloudless, clear and does not have any meteorological features.
- When the night sky is dark with no observable references outside the flight deck.
- When the surrounding is hazy, causing a distortion of the surrounding environments.
- When there is strong sun glare or bright glaring lighting.
- When the aircraft is flying over a ground totally covered with snow, over a desert or vast water bodies with no visual references on the ground.
Solutions
- Practise looking at objects at a far distance, in order to strengthen the eyes’ ability to attain distant focal points.
- Pilots should focus at wing tips of his/her aircraft as a visual reference.
- Pilots should fly above layers of haze or smoke.
- Pilots should utilise the practice of peripheral vision towards recognising movement detection due to a more effective response of this method towards detecting weak stimuli related to small movements, as compared to maintaining a central focus point.
References
EUROCONTROL. (2010). Empty field myopia. Retrieved 4 September 2010, from http://www.skybrary.aero/index.php/Empty_Field_Myopia.
Federal Aviation Administration. (1983, March 18). Pilots’ role in collision avoidance. Retrieved 7 September 2010, from http://www.skybrary.aero/bookshelf/books/797.pdf.
