Final answer:
When flying at night, vision can be impaired by light pollution obscuring faint stars, atmospheric absorption of starlight, and turbulent air distorting celestial views.
Step-by-step explanation:
Three aspects of vision that degrade when flying at night include:
- Light Pollution: Artificial lighting from urban areas can scatter in the atmosphere, creating a glare that obscures the visibility of faint stars and celestial objects, thus reducing the capability of our eyes to adapt to the darkness and see dimly lit objects in the night sky.
- Atmospheric Absorption: Even in clear sky conditions, the atmosphere can filter out starlight, particularly in the infrared spectrum due to water vapor. This atmospheric effect limits observation capabilities, decreasing the amount of starlight that reaches the viewer's eyes at night.
- Turbulent Air (referred to as 'bad seeing' by astronomers): Unsteady air causes light to twist and bend, leading to blurred and distorted vision while looking at distant objects or navigating using celestial sightings during flight at night.
These factors combined significantly impair night vision, which is critical for pilots and those navigating at night.