Why might NVG users employ a red filter?

Using a red filter with night vision goggles is primarily aimed at preserving the user's night vision while simultaneously reducing visibility to others. The human eye is less sensitive to red light, allowing users to maintain their ability to see in low-light conditions without fully compromising their visual adaptation.

This characteristic is especially important for military and tactical operations where stealth is crucial. The red light does not significantly affect the performance of the night vision equipment, enabling the user to accomplish tasks without losing their night vision capabilities. Moreover, by using a red filter, the light emitted does not attract the same level of attention as other colors, allowing users to remain discreet in their environment. This aspect plays a pivotal role in operational effectiveness during nighttime missions or activities that require low-profile visibility.