Definition
A condition in which the body, or a specific part of it such as the eyes, receives less oxygen than it needs to function normally. In flight, it is typically caused by reduced atmospheric pressure at altitude, which lowers the amount of oxygen the lungs can absorb into the bloodstream.
Plain English
Not getting enough oxygen. As you climb higher, the air thins out and your body takes in less oxygen with each breath, which can affect how well you see, think, and move.
Context Anchor
Seen in discussions of vision, night flying, altitude, and pilot physical limits.
Derivation
From Greek 'oxys' (sharp, acid) and 'genes' (forming) — oxygen was named as the element thought to form acids. 'Deprivation' comes from Latin 'deprivare', meaning 'to take away'. Together: having oxygen taken away.
Why Pilots Care
It impairs night vision and instrument scan accuracy well before other symptoms appear, creating a serious safety risk at altitude.
Grounding Statement
At altitude, every breath delivers less oxygen than the same breath at sea level, and the body — especially the eyes — notices first.
Intuition Check
Oxygen deprivation does not only mean having no oxygen at all. It can mean having less oxygen than your body needs for normal vision, thinking, and alertness.
Example Sentence 1
Climbing to 12,000 feet without supplemental oxygen, the pilot began to experience mild oxygen deprivation, and her ability to read the instruments at night noticeably declined.
Example Sentence 2
Supplemental oxygen is required to prevent oxygen deprivation when flying above 10,000 feet for more than 30 minutes.