Plain English Meaning

A dizzy, queasy, or disoriented feeling brought on by a fast flickering light in the cockpit, such as sunlight chopped up by a spinning propeller.

Full Definition

A disorienting physiological reaction caused by exposure to flashing light at frequencies roughly between 4 and 20 cycles per second. In aircraft, it is most often produced by sunlight passing through a slowly turning propeller, a strobe reflecting off cloud or haze, or rotating beacon light entering the cockpit. Symptoms can include dizziness, nausea, confusion, headache, and in rare cases seizure-like reactions.

Context Anchor

Seen in aviation human factors discussions, especially when flying toward a sun or when flashing light passes through a propeller or .