Red-eye flights refer to overnight flights that depart late in the evening and arrive early the next morning. These flights are named after the red eyes that passengers often experience due to lack of sleep. Despite the inconvenience of flying during the night, red-eye flights offer several advantages. They are often cheaper than daytime flights, less crowded, and can allow for maximizing the time spent at a destination. However, passengers should be prepared for the challenges of sleeping on a plane and may need to adjust their sleep schedule to minimize the effects of jet lag.