By means of this spell the caster can see astral, ethereal or invisible creatures.
The Netbook of Witches and Warlocks
By Timothy S. Brannan and The Netbook of Witches and Warlocks Team
She is limited only by her own sight. Even though the caster can see the creatures or items in the astral or Ethereal Plane, she may not be able to effect them. Plus the creatures may not be able to see the caster. Any gaze attacks that can extend into the astral or ether will also effect the caster.
The material component for this spell is a bit of special blue power that the caster uses to draw an eye on her forehead.