The most important thing to remember is that in perfect conditions the very best visual acuity you can get from a GEN 3 NVG is 20:200
What does that mean?
Well, you could claim a disability benefit for being "legally blind".....and you can never hold a drivers licence.
Of course its pefectly OK to fly around 'safely' at 25ft, 140kts at 0.2mLux, being shot at!