Why should divers avoid using bright lights unnecessarily?

Using bright lights unnecessarily can significantly disrupt a diver's night vision. When diving in low-light conditions, the eyes take time to adjust to the darkness. Bright lights can momentarily blind divers, making it difficult for them to see in the dark after the light is turned off. This disruption can affect overall visibility and safety, as it impairs the diver's ability to navigate and identify potential hazards or marine life.

In contrast, it's essential to utilize light judiciously, reserving it for specific situations, such as illuminating important areas or signaling, while allowing for the natural adaptation of night vision. By doing so, divers can maintain better awareness of their surroundings in the dark, enhancing their safety and enjoyment of the dive experience.