Quick Question about Multiple Vision Ennhancers Options

[Sage2000]

Good evening.

I was wondering about the multiple possible layers for vision ennhancers, and how they would interact.

In terms of RAW, can a character stack, say:

- Natural elf vision (low-light);
- Contact lenses with enhanced vision (bonus to perception);
- Googles or helmet with a bunch more, like thermographic, magnification, etc.

My main concern is that all that stuff thats eletronic/digital would not work well in layers. The googles for example would not let the ambient light pass to the users eyes so the elvish eyes could function.

Besides that seems that the game designers would like us to use one of them at a time, thus the limits would make sense.

A second question would be: could the vision "modes" be functioning at the same time? Say thermo + ultrasound ? Seems a little imbalancing...not forcing us to make choices.

I would like to hear from you fellows, in terms of RAW, not house rules (I will create mine if needed).