What should a pilot avoid for at least thirty minutes before a night flight to help their eyes adapt to darkness?

To help the eyes adapt to darkness before a night flight, pilots should avoid bright white lights for at least thirty minutes. The reason behind this is that exposure to bright light can significantly hinder the eye’s ability to adjust to low-light conditions, which is critical for night flying. When the eyes are adjusted to darkness, they become more sensitive to light, allowing the pilot to see better in dim conditions.

Bright white lights can cause glare, which diminishes night vision. When a pilot's eyes are exposed to such lights, the pupils constrict, reducing their sensitivity and overall effectiveness in low-light environments. This adaptation process is crucial for piloting at night, allowing for a clearer view of instruments and outside visuals.

While other types of lights and screens may also have some impact on night vision, bright white lights specifically disrupt the essential adaptation process needed for effective night piloting.