Casting Time 1 standard action
Does invisibility purge work on creatures that are naturally invisible?
In general, yes–nothing in the spell description says it only works on spells or other magical sources of invisibility. However, note that the invisible stalker’s natural invisibility specifically says that it is not subject to invisibility purge. Thus, will-o’-wisps and pixies become visible, but invisible stalkers do not.
You surround yourself with a sphere of power with a radius of 5 feet per caster level that negates all forms of invisibility.
Anything invisible becomes visible while in the area.