Blind Illusion is an American progressive thrash metal band that was part of the Bay Area thrash metal scene. Formed in 1979 by lead guitarist and chief songwriter Marc Biedermann, the band had an extremely unstable lineup (Biedermann being the only constant member) and even went through a few stylistic changes in their time. They have only released two studio albums throughout their career, The Sane Asylum in 1988 and Demon Master in 2010. Les Claypool (Primus
) and Larry Lalonde (possessed
) are former members of this band. Biedermann reformed Blind Illusion in 2009.