That would give new applications for probiotics…
The various sights can actually reveal a great deal of things, if you know how to interpret an aura.
It also depends on exactly which sight you use (different sights can see some different things).
But in general most sights can see:
2) some indication of animus level/usage
3) some indication of mana level/usage (mana wielding types)
4) strong emotions (rage, love, depression in large quantities)
5) enhanced spectrum (see heat above) and low light conditions
6) sometimes religious affiliation depending on the type of sight and individual (e.g. clerics can often determine religious affiliation, if they are familiar with the person’s relgion)
7) mana/animus binding/level/format (again this is interpretation) so “elf”/”demon”/”spirit”/”human”
A lot of it really is based on ones skill at interpreting the aura, Seers, like Maelen can figure out a lot more about a persons aura than your average demon can, I’m not sure though how much of this is the type of sight as it is the training/experience the person has in interpreting the aura.