I was wondering about the astral sense in both form, when you're astraly active, or astraly projecting.

Do you need to see something to assense it when you're still in your body, or do you feel the presence of an astral being/magical energy/weird astral effect that is behind you?
How about when you're projecting and face a direction? Do you have awareness of astral phenomena only there where your real sight might in theory be, or is it some kind of field that you emite, as you're only a kind of energy when projecting, and having faces and feet is only symbolic?

Is it different when in each form, or similar?

You need to be looking at stuff to see it, regardless of whether you're in the flesh, perceiving astrally, or projecting. Functionally (as in for casting and assensing), you need LOS to your target.

What you see when perceiving is what you see when projected.

Astral perception is not tied to any physical organs, so the way your body is facing technically has nothing to do with it. Most magicians are probably most comfortable thinking of it in terms of "astral sight" and when dual-natured would concentrate in the direction of their physical eyeballs, but there's no requirement for them to do so.

So theoretically, the astral sense is a field of permanent awareness regarding astral phenomena when activated in either dual natured or projected state.

Okay. Thanks a lot.

Or are there other opinions about this?

Yup... You're not limited to sight. You can even astrally perceive smells and sounds, or more precisely the emotional 'colour' of the thing perceived.

In my games astral senses follow more or less the same rules as their mundane counterparts. I figure that's the way our minds have been wired to process information, even when not using the actual sense organs.

I feel it makes things simple and logical. YMMV.