Light is necessary in order to see the main aura of anything. Living auras react in the presence of light - expanding and brightening. This reaction is most noticeable when a living aura is exposed to sunlight. You could say that auras are photo-sensitive.

I have made extensive observations of this light reaction. I have observed the auras of people inside a house, then immediately taking them outside, into the sunlight. The living auras of people expand in sunlight, and are much brighter. They fairly sparkle with life in strong, direct sunlight. I have seen auras expand to several times their normal size in sunlight.

Another interesting observation, that adds weight to this argument, that auras are not light - but that light is necessary, in order for auric sight to work: the main aura cannot be seen in complete darkness. If auras were indeed light, why is it necessary for there to be light, in order to see them? This shows that light and normal optical sight are an important part of auric sight.

Note: In total darkness, it is possible to see some slight activity around the energy body, close to the skin. This is almost invisible, but looks like tiny, very faint strands and sparks of bluish light. This is very faint and most noticeable around your own fingertips, when they are brought together in front of you.

It is also possible to see small but intense points of light, coming from fully active primary energy centres (chakras). These must be extremely active for this to be seen, and you must also be very focussed on your subject. This takes a lot of skill to do, and the subject must be very developed - energy wise - in order for this to be observed. This is far easier to see if there is a little available light, even if you can only make out vague shadows - it gives you something to focus upon.

To observe any part of the energy body, in darkness, memory based visualization is used to focus the brow centre into a subject. You have to know exactly where the subject is (in total darkness) and be able to accurately gauge their distance, shape and position, and see them clearly in your mind's eye.

I think, for the above, that both astral sight and clairvoyance play a part, for those that can see energy activity in total darkness. This appears to be the only logical explanation for this phenomena.

Note: Light is not necessary for clairvoyant or astral sight to work, but the eyes and their normal focussing ability are still used, but with memory based focussing and visualization, instead of normal light based focussing. You can see with astral and clairvoyant sight, just as well in total darkness, as you can in full light.