Currently there is a number of ways to handle flashs in night vision. Flashs and intense light changes can blind a night vision user by being flashing too bright before the goggles can adjust for the users eyes.
Methods exist for flash mitigation in night vision goggles to avoid damage to the eyes, but most of these methods add a slight delay and other complications.
A simple fix for flashs of light damaging the eyes using night vision is to invert the colour of the image, turning white to black when a flash happens, the down side is suddenly turning the lights off rather than on.
Lowering the maximum brightness, or the threshold of brightness in an inverted mode would also be advised with this setting.
Flicking in black offers no sudden light damage to the eyes over a pure white flash, a flash would take longer to recover from overs what would feel like a natural blink of black, which is what the eye does naturally by blinking eye lids.
Both these two setting can be applied with very little complexity, without hardly any processing or delay in image display.
Slightly more complex systems can add other frequency of lights as input, such as infrared, this would help compensates loss of image in flashs by adding an extra overlay on an images.