Absolutely not for tube-based devices. Exposing an image intensifier tube to bright daylight can permanently destroy the photocathode in seconds. Most tube-based devices have automatic brightness limiters for moderate light levels, but direct sunlight is lethal to the tube.

Always use the lens cap when transitioning from dark to light environments, and never look directly at the sun with a tube-based device.

Digital night vision is generally safe in daylight — the CMOS sensor handles high light levels far more tolerantly. Some digital night vision devices include a daylight mode and function as conventional cameras during the day. However, operating in daylight defeats the purpose of the IR-optimized sensor.

A common user error: leaving a tube-based device in a bag where the lens cap comes off. Even indirect strong sunlight entering the objective can damage the tube. Develop a habit of double-checking lens caps before storage.