What environmental factor can impair NVG performance aside from humidity?

High levels of ambient light can significantly impair the performance of night vision goggles (NVGs). NVGs are designed to amplify available light, allowing the user to see in low-light conditions. However, when ambient light is too bright, it overwhelms the sensors within the NVGs, causing a phenomenon known as "blooming." This results in a washed-out image, leading to decreased clarity and effectiveness. Bright light sources can trigger automatic adjustments in the NVG's gain, making it difficult to see in the intended low-light environments. Proper NVG operation relies heavily on the appropriate light conditions; hence, high ambient light can be a critical factor affecting visibility and overall performance.

In contrast, stable ground conditions, lack of wildlife, and dry air conditions do not have the same degree of impact on the functionality of NVGs. While these factors may affect the environment in which NVGs are used, they do not directly influence the optical performance of the devices in the way that ambient light does.