Feat: Ever-Vigilant Senses
Your eidolon has enhanced senses. It gains a +2 circumstance bonus to Perception, and can't be flanked except by creatures that are higher level than it.
It can see Invisible creatures and objects; they appear translucent and are Concealed.
When your eidolon moves within 30 feet of an illusion that can be disbelieved, the GM rolls a secret check to disbelieve it, even if your eidolon didn't spend an action to Interact.