In commercial aviation, a red-eye flight is a flight scheduled to depart at night and arrive the next morning. The term "red-eye" derives from the symptom of having red eyes, which can be caused by fatigue.

What does red eye mean in flights?

A red-eye flight is an overnight flight that departs in the night and arrives at the destination the next morning. When people are referring to red-eye, they're usually talking about a cross-country flight, or a flight across timezones (including some long-haul flights).

Are red eye flights cheaper?

Yes. Red eye flights are usually cheaper. Because of their obscure flight times, red eye flights are usually less in-demand. Therefore, airlines offer red eye flight tickets at a cheaper price as an incentive for passengers to book flights during these off-peak hours.