I've been looking around, checking the books and pyramids I have available (not as many I would like to have though) and I couldn't find a spell that can see through illusion without extraordinary conditions attached (a resisted check against the illusion's caster is ok).
Mage Sight would say the object/subject I see has a magical aura, but not that is a illusion per se.
See Secrets would see a secret passage behind an illusory wall but will not work against the illusion of a goblin walking through a corridor.
Is there something usable for that purpose (of seeing through illusions) available? It can be as specific as only works against illusions or broad similar to D&D's
True Seeing spell.