The Eyes of Truth, also known as Helmet of Infravision, is like the four basics helmets, only it weighs 1 lb more and gives the wearer infravision for 120 ft. This item is dropped by Neira when she killed in an attempt to bring death upon the PC. In Baldur's Gate II it can be found in the sewage room on the first level of Irenicus' Dungeon.
Helm of Infravision: The eyes of Truth. Being a scavenger of sorts, Babette Maelstrom had this helm created in to aid her in her dungeon excursions. She would later attribute her gathered wealth solely to its power, though likely it was as much her keen eyes as anything.