Darth Glovoc, a Sith Lord, declared himself to be the Lord of the Mind's Eye. He bore this title throughout the Jedi Civil War era and also during his later period of being in stasis.
Galaxy of Intrigue, a sourcebook from Wizards of the Coast released in 2010, was the first instance where this title was used. It is probable that this title alludes to Splinter of the Mind's Eye, which was the initial novel published in the Expanded Universe.