Night Vision Equipment

[Flowergarden]

Hi, I have two questions regarding night vision equipment.
First, do my innate night vision stacks with night vision optics?
Second, what penalties would i get for using night vision monocle? I suppose I would get no depth of perception, but what if it's some ultra tech green glass goggles, size of normal goggles, with only colourblindness as a disadvantage. Do I get no depth of perception only in situations when my goggles helps? I suppose even in -9 darkness with naked eye i would see silhouette, supposedly, is it enough to remove no depth of perception?
Thanks