Blindsight

Blindsight is the extraordinary ability to use a non-visual sense (or a combination of such senses) to operate effectively without vision. Such sense may include sensitivity to vibrations, acute scent, keen hearing, or echolocation. This ability makes invisibility and concealment (even magical darkness) irrelevant to the creature (though it still can’t see Ethereal creatures and must have line of effect to a creature or object to discern that creature or object). Blindsight never allows a creature to distinguish color or visual contrast. A creature cannot read with blindsight. Blindsight works underwater but not in a vacuum, even if the creature utilizing blindsight is native to a vacuum space.

Blindsight is closely related to the ability of Blindsense.