What should you avoid using to preserve night vision in lighted areas?

To preserve night vision in lighted areas, it is crucial to minimize any obstruction or interference with your eyes’ ability to adapt to low-light conditions. Sunglasses, which are designed to reduce brightness by blocking out visible light, can create a significant contrast when moving from dark to light environments. This abrupt change can hinder the eyes’ natural adjustment process, making it harder to regain night vision once light conditions change.

In contrast, other options like contact lenses, regular glasses, and protective goggles do not possess the same level of interference with light adaptation. While these may provide some level of obstruction (such as tinted lenses in regular glasses), they do not inhibit the eyes' ability to adjust as drastically as sunglasses can. Therefore, avoiding sunglasses in lighted areas is key to maintaining night vision efficiency and allowing for a quicker re-adaptation to darkness when necessary.